BM257s RELative zero mode (delta)

[negative_feedback]

Hello, I was playing around with this meter and its the only one I have that doesn't "zero out" instantly when in REL mode. Instead, its slowly counts down towards 0.0 and then it kinda stays put, after I restore normal mode it will climb back up in same amount of increments.

I tried to confirm its accuracy with some 200/202 resistors and it was maybe even too accurate . Is it normal for compact DMMs to be lagging like so (tried to find some videos but they usually show this on 800 series)?

PS It is Welectron. branded Edition+ with premium Brymen leads. They show 0.0 or 0.1 resistance so I never needed to zero that out really... unless 257s is totaly of the mark.