it was actually intended behavior and should only happen if a track cannot be found when existing filters exclude the file ie. MB resets the active filter on the column browser, thumbnail browser, etc
However i will look to change it so the library filter is preserved
Well, this intended behaviour may be the right thing, but I can suggest a variant:
If the now playing track does not match the current filter,
keeping the filter won't allow MB to show the track in its album,
unless MB opens a new tab without filter (or an existing inactive tab without filter).
(Thus, something similar to when you click on a link in the Track Information panel: a new panel opens, which matches the search pattern.)
Anyway, with the present algorithm, I've found a case where the filter is reset without need:
- No filter applied.
- Start a track of World Music.
- While playing, apply filter "World Music"
- Select a value in the Thumbnail Browser, then locate the playing track in the library
=> the filter is reset
On the contrary, the filter is not reset if the track was started AFTER applying the "World Music" filter.
While Pai_Natal (the OP) said that the filter reset "happens all the time", I've not been able to find other circumstances than the ones I mentioned.