Active Directory is very slow using Mesh Wifi Orbi RBK50

I was wondering if I was the only one with that issue.

My work requires that I sometimes unlock accounts using Active Directory (connected over a Cisco VPN) and it used to work great from home, but lately since the pandemy, I noticed that it's very slow !!! It used to be as fast as when I'm at the office, but now anytime I just right click on the domain name to bring up the find option, it takes at least 15 seconds!!!

Then searching for an account takes about 30 seconds and opening the account properties takes longer than 30 seconds.

The weird thing is that only AD is slow. Everything else works just fine.

I tried over Wifi and also connected to the router with an ethernet cable, but the result is the same.

I looked at the router options, but didn't find anything that I thought could help fix this issue.

I tried with an older D-Link router I kept home and AD is working fine just the way it used to work on my Orbi system.

As soon as I connect back to the Orbi, AD is slow again.

I'm not sure which firmware version I had when it was working fine, but I had version V2.5.1.8 when I started noticing this issue. I updated it to version V2.5.1.16 (not expecting it would fix it considering it is a minor update not at all targeted for this issue) and as expected it didn't fix the issue.

Is there anyone else having this issue?

Does anyone have any suggestions on what else I could try to fix this issue?

Thanks!