Basically overtraining them due to the pressing work. I actually began incorporating tricep work about 3 weeks ago and so far so good and I feel it's been beneficial to my BP and OHP performance. I added decline tricep extensions for 4 sets of 6-8 reps and superset that with rope extensions for 8-10 reps. Any recommendations to adding / changing my tricep work? I'm not necessarily going for arm hypertrophy but more for adding strength to better support my pressing work.
Edit: Also, at one point my close-grip BP was about 90% of my regular bench press and I was told that my triceps were too involved in the bench press. I stopped doing tricep isolation work and focused on pectoral isolation work to try and help counterbalance that. I haven't tested it recently but I think I'm back in-balance.