Flamingo nxt 5.5 very slow when changing settings

Have noticed this on files and tried to narrow it down. Flamingo control panel will get excruciatingly slow when doing things like changing the render resolution. It doesn’t happen on a new session, blank file, etc. Behavior seems to go away if you close the materials tab, or sometimes if you delete a random material from the material list, it will become speedy again. I currently have a test file that, when opened will be speedy (changing render resolution numbers), but if you simply click on the Materials tab and then back on the Flamingo tab, it becomes slow. If I delete any single material, it will then behave quicker, and I can click on the materials tab and switch back and forth with ease, without a slowdown. However, as soon as I force an “Update Preview now” on any material, the slowdown happens again when entering the Render Resolution.

Flamingo 5.5.18353.6521
Rhino 6.SR22