503 Service Unavailable The server is temporarily busy, try again later!

Hi there this is happening only when i try to go to TDMS settings in admin i keep getting 503.
I have deactivated it and then reactivated still the same.
i turned on the log file this is the what is showing:
[16-Oct-2025 12:29:09 UTC] PHP Deprecated: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated in /home/u768894773/domains/pishopper.com/public_html/wp-includes/functions.php on line 7360
[16-Oct-2025 12:29:09 UTC] PHP Deprecated: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated in /home/u768894773/domains/pishopper.com/public_html/wp-includes/functions.php on line 2195

I have reinstalled it it opened the settings page but as soon as i ticked import categories and tried to save again the whole thing is gone with 503 error.

is passing a null value to String functions (strpos, str_replace) that now require a string type in newer PHP versions. This often happens after upgrading to PHP 8.1 or later, as these versions enforce stricter typing for function parameters.
I downgraded to php 8.0 still the same problem even though i downgraded again to PHP 7.4 still the same problem.

I am in hurry to test this plugin please try to fix the problem

Thank you

HM Dadou