I’ve been encountering this bug for the past 2 days of using MN3. Occasionally, my handwritten would disappear (become blank, just like which underneath the “Pressure” node), or appear as a pink block. In addition, new writing on top of the node wouldn’t register. Every time this happens, I would have to kill the app from the process then reopen it, which is annoying. I’m not sure if this only happens to me.
My device is the Ipad Pro (12.9 in) (5th gen), running iPadOS 14.71.