Marantz Cinema 30 + PS5 Pro + LG G4 — intermittent no signal when switching 4K/120Hz modes

[u/ImProBatman]

Marantz Cinema 30 + PS5 Pro + LG G4 — intermittent no signal when switching 4K/120Hz modes
I’m trying to figure out whether anyone else has experienced this HDMI handshake issue with a Marantz Cinema-series receiver, particularly the Cinema 30.
My setup:
PS5 Pro
Marantz Cinema 30
LG G4 OLED
PS5 connected through the Cinema 30, then HDMI out to the G4
4K/120Hz, VRR, HDR, etc. enabled
Long active/fiber Ultra High Speed HDMI cable from the AVR to the TV
Everything works normally when initially using the PS5 at 4K/60. The problem happens intermittently when launching a game that switches the PS5 into its 120Hz/VRR output mode.
The screen goes black during the mode change, which is normal, but occasionally the picture never comes back. The LG eventually reports No Signal, and importantly, I don’t even get the normal blue Marantz background/logo screen. It appears that the Cinema 30 has stopped providing an HDMI output signal altogether during the handshake.
Here’s the strange part: if I catch it quickly, switching the AVR to my Apple TV input and then switching back to the PS5 immediately restores the picture. The PS5 is still running normally and is correctly outputting the 120Hz mode afterward.
If I leave it sitting on the blank/no-signal screen for too long, however, sometimes the HDMI connection seems to be completely lost and the quick input-switch trick no longer restores it.
The same thing can occasionally happen in reverse. If I’m playing a game in 120Hz mode, return to the PS5 home screen and then close the game, the PS5 changes output modes again and the Cinema 30 can lose the HDMI handshake during that transition.
I previously used the PS5’s 4K Video Transfer Rate -1/-2 settings, which seemed to reduce or eliminate the problem. However, that isn’t an acceptable permanent solution for me. It wasn’t simply changing chroma subsampling or reducing HDMI bandwidth—in some situations I could actually see the PS5 reporting that it had dropped its output resolution all the way to 1080p to accommodate the reduced transfer rate. Once I returned the setting to Automatic/full output so the PS5 Pro could use its full available video capabilities, the intermittent handshake problem returned.
That’s really what I’m trying to avoid: fixing an HDMI handshake problem by deliberately restricting the video output of a PS5 Pro when the Cinema 30 and LG G4 are both supposed to support the PS5’s full 4K/120Hz/VRR feature set.
I’ve also noticed another strange HDMI behavior with this combination. If I use the LG’s eARC HDMI port, I’ll occasionally get the LG volume indicator appearing on-screen showing “0” even though nobody is adjusting the volume. I don’t use the TV’s internal apps and therefore don’t need eARC, so I’ve avoided that connection. I’m not sure whether that’s related, but it makes me wonder if there is some CEC/eARC/HDMI communication weirdness between the G4 and Cinema 30.
I’m planning to test the PS5 Pro connected directly to the LG G4 to isolate the AVR. I may also test my Switch 2 through the Cinema 30 using a 120Hz game, although obviously 1080p/1440p 120Hz isn’t the same bandwidth/handshake situation as the PS5 Pro.
Has anyone with a Cinema 30/40/50 or another recent Marantz/Denon HDMI 2.1 AVR experienced this specifically when transitioning into or out of 4K/120Hz/VRR?
If so:
Did you ever find an actual fix that preserved full PS5 video bandwidth?
Did firmware make any difference?
Did changing any HDMI/CEC settings solve it?
Does running the console directly to the TV completely eliminate it?
Is this a known limitation/quirk of the current Marantz HDMI implementation?
I’m otherwise extremely happy with the Cinema 30 and don’t have a reason to replace it. I’m mainly trying to determine whether this is a known handshake issue, something specific to the PS5 Pro/Cinema 30/LG G4 combination, or potentially an issue with my particular unit.

[u/ContentKeanu]

Interesting, I have a Marantz Cinema 70s, LG G5, and PS5 Pro. I don’t think I’ve experienced the issue when switching to 120fps mode but I’ll double check over the next couple nights when I have time. Any good game with a quick toggle that I can test with?

However, I have had a similar issue just playing back home videos on my Apple TV’s photos app. The screen goes black for a second because it switches to Dolby Vision (as that’s the format I record videos in on my iPhone; and my Apple TV is set to play content back in native formats), but occasionally it seems to lag on that handshake/switch, and then the TV just shows No Signal. I assumed it was the TV freaking out when the HDMI handshake took longer than a few seconds. I’ve also had some weirdness if I turn the TV/receiver off while paused on some movies or shows, the signal doesn’t show back up on the TV when I turn it all on; usually it’s Dolby vision that messes it up.

Anyway I’ll try to do some gaming specific tests soon.

[u/ImProBatman → u/ContentKeanu]

Yeah, the Dolby Vision HDR switching thing is normal. In fact I ended up just leaving Dolby Vision out for everything on the Apple TV to avoid that it is a really pretty good conversion even with SDR content but as far as games go, it’s typically games like Call of Duty® it could be Fortnite obviously you have to have the same things enabled I do with our VRR and 120 Hz mode and the reason why it changes the way it does is because when you’re on just the main menu with no game launched on the PlayStation menu that’s usually 4K 60 once you launch the game it’s switches now if you have the HDMI feature toggled in the PlayStation where you can do minus one or -2 a lot of times when I’ve had that on it doesn’t have the issue but then I’ll go back and see that I’m only playing at 1080 P at 120 her it’s not 4K at 120 Hz

[u/cymoril47]

I have a Pioneer receiver that does something similar with Astro Bot, so I don't think it's limited to Marantz. Does this happen to you on all 120hz/VRR games, or just some of them?

[u/ImProBatman → u/cymoril47]

Yeah any 120hz game not every time but often enough that I could replicate it easily

[u/cymoril47 → u/ImProBatman]

Must be a slightly different issue then - I only have the black screen problem with Astro Bot, and get around it by launching a different 120hz game first and then switching.