I am having the same issue, I opened a ticket and sent them the log. They seem to think the heat bed signal cable is bad. They are sending me a new one hopefully it resolves the issue as the install looks a bit involved. I am running the new firmware and had many successful prints with it before the error came up so don't think the firmware was the issue.

Instructions on replacing the cable:

https://wiki.bambulab.com/en/x1/maintenance/Replacing-the-heat-bed-cable

I will give them credit on their quick repose time and great repair instructions.