Hi @Tony S ,
I test this in my environment, it works well. I also using SSMS 18.8. Did you try to run the SSMS 18.8 as administrator as below screenshot? Did you try to restart the computer if possible?
SSMS 18.8 is supported be installed on Windows 10 (64-bit) version 1607 (10.0.14393) or later. Does SSMS 17.9.1 also have same issue in your environment?
Please also check if this old similar could help you.
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