5RM vs 5x5. Rep/Set Divergence

Hi all,
just wanted to get some views on the following. I’ve been training on a modified TM with some varying assistance work. The core is a 5x5 with 90% of my 5RM on Monday and the 5RM then on Friday. There is a light day on Wednesday, but for the purpose of this discussion it is irrelevant.

I’ve made a fair amount of progress on this and my performance on the Volume Day (5x5) always moved in sync with my Intensity Day (5RM). I have reach a plateau a couple of weeks ago, with a few rep PRs, but things have been going somewhat stale. I am not too concerned about this as my body was feeling the need for a deload and there have been other non-training related factors, which forced me to skip some sets and even training days on occasion.

I am just getting back into a new training block, and found that my Volume Day Performance is significantly better than my Intensity Performance (5RMs). This seems to be the case across Squats and Bench, so not particular to a muscle group. To make this a bit more specific:
Old block:
Squats 5x5 with 125kg[276lbs] and 5RM with 137.5kg[303lbs]
Bench 5x5 with 92kg[203lbs] and 5RM with 102.5kg[226lbs]
New block after deload:
Squats 5x5 with 127.5kg[281lbs] and 5RM with 140kg[309lbs] (can only do 2-3 reps)
Bench 5x5 with 95kg[209lbs] and 5RM with 105kg[231lbs] (can only do 3)

I’ve seen above now for 2 weeks in a row, and I was fairly rested. I’ve also attempted my 5x5 bench with 97.5kg and got 4 sets and the 5th set I reduced down to 92.5kg. It seems that my normal 5x5 seems to progress as expected (given all outside factors), but I might have lost strength on 5RM. I find it odd that I managed to get 5 reps with 137.5kg and only added 2.5kg made this go back down to 2 reps (with RPE 9ish).

Anyone experienced something similar? CNS not fully recovered? Should I have dropped my 5x5 load to match my true 5RM after my deload, i.e. to something lower than my old block’s 5RM achieved?

If you’re squatting 140 for 2, I would have my heavy set on week 1 set to 125kg. You should hit 140 for a very solid 5 in 4 weeks and go from there.