Some boards can not hold overclock. It is rare, but it happens. Your pictures are also small and blurred so I cannot make out a lot of detail. At least in your second picture the pool side average is 54 to 55. That's even with whatever dips you are seeing.
It seems that your miner side average is 55 and your pool side average is 54 -- this looks good. Your pool side dips could be any number of reasons, including random network or pool issues.
The real time is not important -- it is your average (and ultimately the pool side average and share submission rate) that is important. If you are staying in the ~55kSol range and your boards are not dropping, then you are in a good place.
I have 1 board that I constantly have to reset as it goes to 0 -- it's on one system and does not happen on the others. One day it will be fine at 650, the next day it only wants 643. I cannot explain these things.
Jason