I was looking at my sub panel beside my main panel. (It is about 2
feet away and was added a few years ago because of lack of space in
main panel).

I believe I read that the netral and ground busses must be isolated on
a sub panel. When I checked with a continity tester, it beeped meaning
they are connected. This is a Square D Homeline series model number
HOMC2OU100C with a main breaker.

It looks like the bonding screw was removed though? There are two blue
screws one at the neutral lug area and one at the ground lug area. I
removed one and still contnuity. I removed both and no continuity.
These look like the screws you remove to remove the interrior of the
cabinet.

SHould I leave the screws out? Can anyone help me with this model?