I am experiencing the same issue after I updated HA iOS app to 2024.3 (iPhone12).
App is slow, touch inputs takes time to register, page loads and navigation takes time and scrolling is stuttering.
I finally got around to getting python updated to v3.11 and home assistant to 2024.4.4 & the app is now very sluggish. It’s the same across other platforms as well, I have two Galaxy tablets used as wall panels and Home Assisant is behaving the same way on them as well. If I access home assistant via a browser, there’s zero lag. The wife and I are both on iPhone 14 Pro’s.