When you extend an instance of SQL Server on Polyserve, to a new server the startup procedure in the master database is not installed, which if the new instance, on the new server is installed to a different MSSQL.x path, the sql agent service may have issues running jobs, as the sub systems will have different paths.

For my scenario I had 7 machines in a cluster, with an instance SQLTest1 installed on servers 1,2 and 3, with a directory of mssql.3.  This all previously existed and worked flawlessly for many months, but then I needed to setup SQLTest1 on server number 7, this required installing SQL on server 7, and then adjusting the properties in Polyserve to include 7, than failing over to 7.  All this worked great, but further inspection showed that the there were some SQLAgent jobs failing and/or entering a "suspended" state.

A quick review showed that server 7 installed to mssql.1.  Polyserve is supposed to handle this, it does this through a procedure in the master database that is set to startup automatically.  I've seen other instances installed to mssql.1,mssql.2 and mssql.1 and there is no issue, as that stored procedure in the master database handles adjusting sql agent sub systems.  I reviewed the SQLTest1 instance and the procedure was definetly missing.  I manually added the procedure and ran it, now the fail over between any of the servers work.

I can only surmise that the initial virtualization did not add the procedure, because it was not needed, all the sub systems were the same mssql.3. 

I think this may be a bug, it is very simple to fix, the difficult part is recognizing the problem and knowing what the fix is!

I contacted Polyserve on this, and the thinking is that this was caused by the 3.4 to 3.6 upgrade and would not happen on an instance that was "fresh" on 3.6 from day zero, makes sense.