Waterproofing joins in plastic splashback?

[SRJDIY]

My bath/shower is lined with plastic splashback panels. The sealant around the bath is getting mouldy and it seems like the gaps between the panels are as well (I've attached a picture). I suspect that water is getting inbetween the panels. If that's the case I can remove the existing sealant, run a dehumidifier in the room to dry everything out, and then reapply the sealant, but I assume the issue will just come back as long as water can get inbetween the panels.

Does anyone know how best to waterproof the joins where the panels meet? The only thing I can think of is to use sealant, but I feel that's going to just splodge everywhere and make a giant mess. Has anyone done anything like this before, and if so what would you advise?

Thanks in advance for any advice!

 

[foxhole]

Joins should already be waterproof by design .Mould is a result of poor ventilation, apply mould remover and ensure room is ventilated effectively .

 

[SRJDIY]

Joins should already be waterproof by design .Mould is a result of poor ventilation, apply mould remover and ensure room is ventilated effectively .

I'm sure they should be, but when I previously replaced the sealant there was some water that came out from behind it, which suggests to me that water's getting in between the panels somehow. Possibly where two panels meet, possibly where they meet via that plastic join in the corner (which does seem like it's not meeting flush with the panels).

I'll make sure to apply mould remover though. The bathroom has an extractor fan which vents outside and we always open the window while showering, so I'm not sure what else we can do on the ventilation front.

 

[foxhole]

More efficient fan , does it have run on after lights off?