I just found a limitation in the APM 'Application by Current Status' resource which limits the filter to 200 characters.
Is there a way to increase this? My query is currently 214 characters and I have pruned it as best as I can.
This is for APM 3.1
Support confirms you've hit the character limit for that field. I'll open a feature request to allow longer filters.
If it's not confidential, can you give me an example of a long filter you would like to use? A real customer example is always a good thing to have in a feature request.