I have the same issue. We have 30+ server, one central NMC. Some of the servers are showing correctly, some are not. If you open the GUI directly from the backup server, it works fine.
It's NW 184.108.40.206, all windows environment.
If you do not already have a Support SR open with DELL EMC I would suggest you open one and request hot fixes from the following escalations which should be applied on to of 220.127.116.11: -
These two hot fixes should be included in later Cumulative releases but did not make into 18.104.22.168.
I updated several servers and NMC now to 22.214.171.124.
till today the console is running fine and without any issues regarding correctness or showing wrong symbols.