Marker.io is used by our team and our clients. We receive issues from both of them. We are also using the different issue types. It results in the Issues open tab to be a mess. The filter is not always working fine (showing improvements in the bug filter) and it is not kept, a refresh and the filtering is gone.
It could be create to create our own views in tabs based on our filters.
For a quick work around, it could already be interesting to have 2 available views : bugs and improvements.