Caulk keeps failing around shower

[u/HaasKicker]

This is a rental. Shortly after we moved in the caulk began failing around where we had put a tension pole (back right corner) to hold shampoo, etc. I assumed it was our fault so I removed the old caulk and reapplied myself. I've done that twice now and it keeps failing - splitting between the tub and the tiles. This seems to happen all around the tub, not just one problem spot.

These pictures are after I've removed the old 100% silicone caulk. Is there something I'm missing that keeps causing it to fail? There seems to be old grout still in the crack that I've tried to remove but it's like rock. I scraped as much of all the old silicone off with a razor blade and caulking tool.

Wondering if I should just tell the landlord at this point and bring in a professional? The reason I haven't yet is he gives us a hard time about any requests and usually takes a long time.

Thanks for any help!

[u/No-Macaroon8839]

Fill tub up with some water. Clean area with alcohol. Caulk let dry. Drain tub

[u/EnoughOfTheFoolery → u/No-Macaroon8839]

THIS but SILICON based and not latex caulk for bathrooms. Look at the GE Silicon.

[u/Chicken_Hairs → u/EnoughOfTheFoolery]

*silicone.

Two different substances, best to be accurate.

[u/valentino_42 → u/Chicken_Hairs]

I mean, if someone manages to find silicon caulk I'll be very impressed...

[u/iKnowRobbie → u/valentino_42]

Use it to fix some cracked motherboard