Hello

1.)Decorous Theme Site menu doesn't open in Application view

The problem was reproduced. We'll investigate and fix it.

2.) Artificer Theme Site menu opens but doesn't fully scroll down in Application view on Mobile

Already fixed: https://github.com/unaio/una/issues/4161

3.) Search bars across all themes do not show search results and give Database Query Error

It would be great if you provide us with the exact DB queries with errors. The issue may appear because of some problems in 3d party modules.