Can overhead Squats,Lunges negatively influence Bench pressing!!

I was doing a program for bench pressing with boards 2 and 4 boards 2 times a week and 1 time a week a progressive overload program with the normal Bench press.
In week 4 I pressed 115 kg with the 2 board and pressed 2 x 2 reps with 107,5 kg in week 6.
Today I tested my records on all 3 powerlifts and especially the bench press was very dissapointing.At 100 kg I barely made 3 reps while a week ago I made 100 x 3 very easy.
So this started me thinking about what I changed last weeks in my programs.
About 3 weeks ago I started doing overhead Lunges and 2 weeks ago also overhead Squats as a warm up before Squats and Deadlifts.Also I started doing illegal wide benches 2 weeks ago.Since introducing these exercises my performance on benching has gone downhill.Today with my test I tried 115 kg but before I tried I knew I wouldn’t make it because I felt I failed muscle tension while lowering the bar to my chest.
The bar just dropped dead on my chest as if I was powerless.
Could it be that those exercises are not meant for me because after training and during the night time my shoulders get really stiff almost painfull
I think I will drop these exercises in the future.
Any suggestions or advice would be appreciated.