we started the test again with the trace:
UC_SYSTEMSETTINGS were (20602,20603)
See WP Log 1 (excerpt)
20220623/123525.121 - U00011847 'SERVER_OPTIONS' set to 'NNNNNNNNNNNNNNNN'.
20220623/123525.121 - U00011847 'SMGR_PORT_RANGE' set to '(20602,20603)'.
20220623/123525.137 - U00011847 'SMGR_AUTO_SCAN' set to 'YES'.
Trace to: 20220623/123209.543 - 45
Then test: Renew Service Manager link
Result: Link not renewable
12:33 p.m.: UC_SYETMSETTIGNS back on (20602,20604)
Then test: Renew Service Manager link
Test result: Link is renewable
UC_SYSTEMSETTINGS back to (20602,20603)
Test: Link is non-renewable again
End trace 12:35
Release : 21.0.3
Component : AUTOMATION ENGINE
They classified this issue as a bug and worked on the correction. This bug has been fixed and the correction will available in version 21.0.4 of the Service Manager.
Bug ID: AE-29125
Bug Title: SMGR link refresh doesn't work if SMGR_PORT_RANGE contains only 2 port numbers
Solution : A problem has been fixed where refreshing the service manager link of agents failed when a port range was used. The last port in the range was ignored.
There was a regression of this issue in 21.0.4 as well and was worked on the bug AE-29847
This is resolved in 21.0.6 which will available shortly