I have this issue on my H7600 and it seems to be getting worse. Just emailed support about it today. I used to have a H7000 and it was really snappy and fast.
I spoke with support and they say it’s normal operation. IMO, the most likely reason is the display/ui was allocated a tiny amount of CPU resources. I was also emailed a beta version which someone else said should alleviate the problem. But I haven’t loaded it yet.
I gave up on experimenting with the factory presets for now at least. I tried around 15/20 at the most before I got a big headache. Keep in mind, if you save them as user programs then filter only for user programs they scroll a lot faster. That is probably the only realistic way to use them, but ideally, you should pick as few as possible, because the more there are, the slower it scrolls.
Anyhow, instead I’ve started making my alg’s using VSig and the results are top notch. I’m not even doing anything fancy, I found a program with some ERs and reverb and hacked it up to something even more simple and this box sounds really good. After using VSig, I can’t imagine selling it.