nimh batteries 1.36v full charge from S2 charger?

I have a few AAA and AA Ni-MH batteries, mostly energizer & duracel they were bought locally at walmart or grocery store in pack of 4 however long ago,
I bought an Eastshine S2 charger off amazon a few months ago and when charging the few N-MH batteries I have and these have been only AAA or AA,
after the batteries get to full on the S2 display saying 1.50v, I take the batteries out.
Anywhere from 5 minutes to a few hours later if I put those same batteries back in the S2 charger it shows either 1.36v or 1.39v and the display is one bar short of full and blinks to charge. After about 10 minutes not more than 30 minutes, the battery is back at 1.50v on the display showing full charge.
Is this normal?
I use the batteries in either an xfinity remote or a little mp3 player in car, and they work for the most part.
I’ve used the S2 charger to do a 18650 or 26650 Li-ion battery from my bigger led flashlights and it seems to charge those just fine a fully charged li-ion battery going back in a few hours later shows the same full charge voltage it did when i took it out as far as i can remember.

This behavior is normal. 1.5v is fully charged on the charger but they will quickly settle to around 1.35v which is the normal resting voltage at 100% charge. No need to put them back on the charger at that point.