Shower tray sunk

[Mr Retirement]

Hi, I have a Chausson Flash 04 and the shower/toilet tray has sunk in the right hand corner, this causes the Tambour semi circular door to come off its runner.
Has anyone else had this issue and is there a way of taking the lower panel off so as to try and put something under the tray to try and reset the tray height and stop it from happening again.
We don't use the shower but we do use the toilet quite a bit! So I need to find a solution as it is only going to get worse. Thanks

 

[Carpmart]

I would be looking into what has caused it to sink first, then when that is established, remove, repair and refit. It’s possible the floor below the shower is damaged..

 

[The Wino]

I think it needs investigating. On both our chausson there was a (very limited) access to underneath the shower tray. It could be that you have a leak on the pipework and rot under the tray ( hopefully not) it needs looking at before it potentially gets worse