Hey there,
I have a 1.2+ MB org-mode file and have been getting the following 
message for a week or two.  I have cleaned up content by archiving older 
content and have run org-lint to cleanup some syntax issues ...

How to debug this type of issue?

Warning (org-element-cache): org-element--cache: Unregistered buffer 
modifications detected. Resetting.
If this warning appears regularly, please report the warning text to Org 
mode mailing list (M-x org-submit-bug-report).
The buffer is: plan.org
  Current command: (org-agenda 4070 5168)
  Chars modified: 4070
  Buffer modified: 5168
  Backtrace:
nil Disable showing Disable logging

Thank you for your guidance.