Interface option breaks auto refresh for some update types

[cfhsncb]

Describe the bug
Enabling the interface option "Only show a tray icon..." appears to break the auto refresh settings for FlatPak and Spices update types. System package updates still respect the selected auto refresh options but the other update types will auto refresh with the default frequency.

To Reproduce
Steps to reproduce the behavior:

1. open update manager
2. file > preferences
3. enable the "Only show a tray icon when updates are available..." option.
4. enable "Refresh the list of updates automatically" option.
5. Increase the "auto refresh" options to a value greater than the default.
6. Under the "Packages" tab ensure "Cinnamon spice updates" and "Flatpak" update types are enabled.
7. Observe that the update manager will show available updates for Flatpaks and Cinnamon Spices before the selected auto refresh duration is reached. (tray icon will appear with orange dot indicating updates are available)
8. Observe that updates for system packages WILL NOT be shown until the selected auto refresh duration is reached.

Expected behavior
All updates types should respect the selected auto refresh duration when the "Only show a tray icon..." option is enabled and the mint update tray icon should remain hidden until the user selected duration is reached (and updates are available, of course).

Distribution:

• Linux Mint
• LMDE
• Other (please specify)

Software version:
Linux Mint 21.3 (in-place upgrade from 21.2)
Cinnamon 6.0.4
mintUpdate 6.0.9

additional notes

• I am aware that rebooting "resets" the auto refresh duration timer and will cause update manager to execute the "First, refresh the list of updates after:" refresh. This issue occurs when the system HAS NOT been rebooted.
• All update types seem to respect the selected auto refresh options as long as the "Only show a tray icon..." option is DISABLED
• Seems to be related to a prior bug reported here: Some update manager option combinations break Auto-Refresh options #167