Help! Shower suddenly not draining

[lazyakita]

I'll try to be brief! We moved into a new house recently and the shower has worked normally. We had a fan and some lights replaced yesterday, showered after and no issues. I just had a 3 minute shower and it suddenly isn't draining at all! I've tried to mop up excess but it's too much to get rid of. I can't remove the trap, it seems sealed in somehow? I do have a bottle of drain unblocker but all I'd be doing is pouring it into a puddle of water :( Please help! Photo of drain attached.

That's also why the shower was blocked, everything draining from the bathroom was getting stuck.

Oh no that’s awful. Both for the neighbour and for you.

So distressing when you’ve moved into somewhere new and it becomes this stressful.

Thank you, both. We've got someone round to check their electrics are safe as it was coming through a light fitting. We will also pay for any repairs, decorating and cleaning, of course. I love the new house but with each day it's becoming increasingly apparent that they did nothing but the bare minimum to maintain it and we are now left trying to put everything right, which is stressful, time consuming and expensive.