I have the same issue… I use woffice theme (themeforest)
debug.log show this if I activate ONLY Buddypress plugin without no other one…
[12-Dec-2023 14:48:45 UTC] PHP Deprecated: str_starts_with(): Passing null to parameter #1 ($haystack) of type string is deprecated in Path….\wp-includes\class-wp-styles.php on line 430
