This has been happening from time to time on 2021R2. Updating to R3 and R4 the problem is very pronounced; I can't seem to go 15 minutes without the charts freezing up.
NI9234 modules x 5, 3 channels each, total 15 channels all at 25,6kHz
18 further calculated channels - mean and rms of above
one more plugin channel @ 2kHz
I've got another thread describing the charts continuing to display uninterrupted but the saved data is missing. Not sure if it's the same problem manifesting slightly differently or a different cause. If there are some diagnostics I could run when it's frozen it may help understand better, as it's fairly repeatable with the new releases.