I raised this issue earlier in the year but it has become evident again.
When I "hold" a system the HP jumps to the first system (alphabetically) in the active scan list. The hold remains but not on the system I desire. This occurs when using the full database with or without GPS active. I tried holding on different systems but it always reverted to the first system in the scan. I did not notice any other events which could have triggered the release of the desired hold. I did not try this on a favorites list but will later today.