Trevor,
Glad you had a better guiding session
This pdf from PHD2 is well worth a read as it does give some indication of issues arising from time to time.
Looking at the graph doesn’t give you the full picture on a problem but does provide a possible idea what it could be as a starting point
Guide logs submitted to PHD2 for evaluation are the best way to go
https://openphdguiding.org/Analyzing...Guide_Logs.pdf
Cheers
Martin