Yeah it is a lot of Hue products. My whole house is lighted by Hue. Should be a strong Zigbee mesh though. I would think the more the better in this case.I skimmed the thread so I apologize if this has been addressed.
How many bridges do you have and how many devices are on each?
I've removed most of my Hue lights and replaced them with normal LED bulbs and smart switches. Over the course of doing this I noticed improved performance of the Hue app. Now that I only have 1 bridge with 6 bulbs it launches near instantly and never crashes. All my automations and scenes are done through the Apple Home app, so I don't really have a reason to open the Hue app.
Point is, in my experience loading and managing tons of devices introduces a bottleneck somewhere that manifest in the app.
I previously had eight V2 bridges with each not exceeding 50 lights and leaving room for a little growth. Plus they were strategically placed for the best Zigbee mesh
Now I’m at three Pro Bridges but nowhere near the cap on each. I had this app issue with the V2 Bridges and now the Pro Bridges and it coincided with an app update, about two updates ago.