Resistance to Groundable point measurement

I am getting resistance to groundable point measurement is too high. what could be the reason for this?

Before I can answer, what is it you are trying to measure? Is it a worksurface, floor, garment or something else.

I am traying to measure worksurface.

I would check point to point on the mat to see if the worksurface is the problem. If that is good, then the connection from the mat to the groundable point must be the issue. Install another groundable point to try to clean or take apart the one there and reconnect.

Is this a soft mat or a hard laminate?

We checked point to point on the mat, it’s good. connection from the mat to the groundable point is not the issue either.
All these workbenches were passing couple months before and now they are failing. only one are passing which we have replaced with new mat and groundable point.
how come suddenly all groundable point can fail?

These are soft mats.