wow - that is a tough one.
it sounds like something pervasive in the environment alongside of Patrol. Possibly a recent windows patch? (but then others would report it). Or perhaps another utility (anti-virus)?
is it possible there is a policy that is common to those systems?
i'm assuming no event logs correlate?
if you restart the server does patrol immediately get stuck or can you stop patrol at will until xyz minute later?
Once the patrol agent gets stuck in stopping status and the server is rebooted, it seems as though everything returns to normal. I can restart Patrol over and over again with no issue. Our basic windows policies are common to those systems, but nothing has changed with those policies recently. I had not considered antivirus, thank you for that idea.
We suspect a recent windows patch as well, since this issue has developed after the last patching cycle. Our system administrators have identified a possible patch and are testing uninstalling that patch. You're right though, if it were a patch I would suspect others would have the same issue and I wouldn't be the only one on communities asking about it. Thanks Michael.
Some of the Windows patches from July have been identified as the root cause of this issue. There are several mentions online of this causing the same issue for other applications and services as well. I opened a ticket to BMC support shortly after this question was posted here. They mentioned that they had 4 or 5 other customers report the exact same issue.
There are several articles online which cover this. If anyone else experiences this issue, there should be many resources online that explain the issue, suspect patches, and resolution.