I was having no problem benching 185 for 5-6 reps for 3 sets when I was in a deficit eating around 2000 calories...

Now I've raised calories to around 2500 and my bench has gone the last few weeks... Can barely get 3 reps with the same weight.

Something else in your training has changed

take a week off

id say this unless you deloaded recently

I do a PPL and I think the only time I've taken off in months is 3 days , so just missed one half of my normal 2x per week ppl

deload bro on 80%
its normal cant bro, push ur max like all the time!

Well it's said that eating a deficit/fasting can increase testosterone levels.. But I think your problem(as is mine and many others) is not enough back/shoulder work. Bench press is an excellent exercise, in fact it's so good it's easy to create an imbalance. If you think about it, if you arms could rotate as far back as they could forward this wouldnt be much of a problem because you could do back bench lol.

TL:DR: back needs far more volume than chest and chest will get stronger as a result. Only way to hit 405 for me was to increase rows, sometimes chest plateaus as a result of other muscle weakness

when i did lots of snatches back in the day my bench went way up.

i kinda agree with this.

Well on back day I do

Barbell rows, pendlay rows, pull-ups, rear felt flies, face pulls