In Exchange 2016 and 2019 you have an option to view your queues with Queue Viewer from the Exchange Toolbox as shown below:
What I have noticed with the new Cumulative Updates (CU) in both Exchange 2019 and Exchange 2016 is they get stuck loading each time the Queue Viewer refreshes itself or if you refresh and quickly refresh again then nothing happens as shown below:
This might be a bug in both versions as PowerShell works fine:
No error is logged in event viewer or displayed on the screen in the Exchange Toolbox. I will update to CU5 for Exchange 2019 and CU16 for Exchange 2016 to see if it makes a difference. (both released on 17 March 2020)
Hope it helps.