Plugin name filter not working anymore

When choosing a plugin in ARDOUR 5.12 there’s the filter option, e.g. “name contains”, “Category contains”, etc.

The filter was working previously, but now it doesn’t.

This happens only with existing projects. When I make a new one it’s working.

edit: “Not working” means that when I search for e.g. “zyn”, nothing is found, although there’s zynaddsubfx, ,etc.