Windows Server 2016 Intermittently Slow

[MS_CAS]

Hi

So I have two Windows Server 2016 (1607) they are RDS servers they do run SQL but the CPU is not massively high on them.  The both run on ESXi 6.5.  Latest hardware and tools applied.  Both servers run the same AV the same FW rules, etc.

They connect to a file server which is running Windows Server 2019 (1809).

For some reason only one of the RDS servers will be a pain.  The other one will run fine.

So for example:

01 - Fine

02 - Painfully slow

Logging on to 01 takes around 5 seconds.  Logging on to 02 takes around 3 minutes - stuck on either applying the printer GPO or the drive mapping GPO.  When logged in people will get a blue wheel when accessing file shares or such like.  The file shares will just hang when browsing but then return fine.  On the other server it's fine.

I've checked and they're both running SMBv3 to all connections that I can see.

I have completely ran out of ideas on what could be causing this.

Anyone have any ideas?

Thanks!

[#2]

These sort of things usually stem from incorrect or problematic DNS settings / setup. I'd check the domain controller and problem members have the static ip address of DC listed for DNS and no others such as router or public DNS

[#3]

@Dave Patrick 

First thing I checked:

01 --> Primary is DC01 --> Secondary is DC02

02 --> Primary is DC01 --> Secondary is DC02

DC01 is a DNS server with two forwarders to Google

DC02 is same as above

[#4]

I'd check the problem members settings. Also check the domain health is 100%

[#5]

No errors in DCDIAG - I'll rejoin them to the domain though just as a quick check.