I've been rather shaken with my recent progress, and I thought I would ask. Just today, I went into the gym and benched 225 5 times, although I usually am able to do it 8 times. Could such a significant strength loss be due to minor shoulder and tricep soreness from exercise two days ago? Also, I have fluctuated in body weight, from 168 to 170, although that is a positive gain. Please add your two cents.
That isn't a normal workout variation, but it is common. Rest longer, push harder next time. Modify your split to include triceps no more than three days after bench.
I recall dropping from 173 to 160 in two days for a crew meet. Gained it all back the day after. One could easily attribute a 2 LB fluctuation to water weight. Consistently higher readings would be an indication otherwise.
Since the triceps and shoulders are heavily involved in the bench press there's a good chance those muscle groups weren't recovered enough for your heavy bench session. If you continue using the same split next time you do the shoulder and tricep workout try terminating each set short of failure if you haven't been doing that. Sets taken to exhaustion and failure are the ones that really negatively effect subsequent strength workouts in the days following.