Electrolux Dispenser Won’t Close

Hello, after some advice please my ESL 66010 tablet dispenser lid won’t stay shut. Doesn’t seem to be damaged or worn so don’t understand why it won’t stay down.

So instead of buying a whole new dispenser unit I have a few questions:
– is this a normal wear and tear issue (over 5yo)?
– what causes the lid to open during a cycle?
– what time in the cycle does it release?
– can I just put the ‘plastic’ tablet in the bottom of the unit instead or even on the cutlery tray so that it doesn’t dissolve too quickly at the base?

Any advice is greatly appreciated. Than you.