This is my first time sending mail to the list so let me know if I
breach any convention.

I seem to be one of many people who have been having issues with
org-element--cache recently. I have been getting the messages quite
regularly in many different cases, but I finally pinpointed one of the
apparent causes: running org-toggle-heading, org-toggle-item, and
probably other org functions that modify the structure of the org document
on a line beginning with a capital letter from a language (not special
font/mathematical characters, but not limited to the Latin alphabet).

I expected to run org-toggle-heading, the line to be converted into a
heading, and no error messages to be thrown.

While the line was properly toggled into a heading, there was a cache
warning that said the following:

Warning (emacs): org-element--cache: Unregistered buffer modifications
detected. Resetting.
If this warning appears regularly, please report it to Org mode mailing
list (M-x org-submit-bug-report).
The buffer is: cachebug.org
 Current command: nil
 Backtrace:
"  backtrace-to-string(nil)
  org-element--cache-sync(#<buffer cachebug.org>)
  apply(org-element--cache-sync #<buffer cachebug.org>)
  timer-event-handler([t 0 0 599999 nil org-element--cache-sync (#<buffer
cachebug.org>) idle 999999])
"
Here are the contents of the buffer showing the things I tested.

------------------------------------------------------------------------
# Cause the Warning
S
R
Ξ
A
S2
X こ
T 漢字
Д
Ԋ
𐲱
Ѷ
# No Problems (= R= is single use)
𝞡
ℤ
/
s S
 R
nA
漢字
2S
_W
/W
s
こ
2
@
_

------------------------------------------------------------------------



Emacs  : GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version
3.24.20, cairo version 1.16.0)
 of 2020-09-19
Package: Org mode version 9.6 (9.6-??-d4e1925 @
/home/pete/.emacs.d/.local/straight/build-27.1/org/)

current state:
I deleted all settings with no mention of 'cache' because my email client
seemed to be having issues with the length of my message.
==============
(setq
 org-persist-before-write-hook '(org-element--cache-persist-before-write)
 org-persist-before-read-hook '(org-element--cache-persist-before-read)
 org-persist-after-read-hook '(org-element--cache-persist-after-read)
 )