@xiongfeiyan, are you comfortable making PHP changes?
My next step would be to add a line (or lines) of debugging code into the module that processes the logs into metrics.
I’d be particularly curious if this code is causing the line to be skipped:
A suggested change would involve adding an error line, similar to the earlier invalid log entry message:
There is a report of a similar situation by @ajnyga here, which you may want to follow, even though the version is different: