Software sources are behaving strangely when an app is available as Snap

This happens on the latest GNOME Software 3.34.2 on Ubuntu Focal. When an app is (also) available in Snap Store, its sources showed in the "Sources" drop-down list in window header on app details page are behaving strangely:

- When an app is available both in the Ubuntu repository and in Snap, default source displayed is "Ubuntu" although the actual details page displayed is for Snap version.
- When clicking the drop-down list and selecting a Snap source, the Ubuntu source disappears.
- When clicking the drop-down list and selecting an Ubuntu source, the whole drop-down list (so basically all Snap sources) disappears.
- Default source is displayed as "Ubuntu" even for apps that are not available in Ubuntu repositories, only in Snap Store (for example the powershell).

This was in GS log, however I am not sure if it is related to this issue:
12:23:31:0206 GLib g_str_has_prefix: assertion 'str != NULL' failed
12:23:31:0215 GLib g_variant_new_variant: assertion 'value != NULL' failed
12:23:31:0215 GLib g_variant_new_variant: assertion 'value != NULL' failed
12:23:31:0215 Gs not GsPlugin error g-io-error-quark:35: Invalid string value converting to GVariant
12:23:31:0270 Gs not handling error failed for action refine: Invalid string value converting to GVariant