I and some others I know also have this issue, at random times and intervals. I very much suspect it's something leftover from this issue.
Here's an excerpt from the similar topic on the iniBuilds Discord server:
Pitch Trim 1 faulted, inhibiting FD1. Noticed the standby attitude indicator was rolled/failed. Then, checked all systems, and noticed any fuel in all tanks except the OUTERs were gone and zeroed. However, no other values noticed were affected, including APU Oil quantity. Fuel also proceeded to flow at a conspicuously high rate, and the FUEL USED counter on ENG 1 was jumbled and appeared to be a large number.
There are some additional posts and mentions in this topic on Discord