PHP Error on "Add new Vendor" back-end

Hello,

When I try to create a new vendor from the back-end, I get the attached screenshot error. This issue only occurs in the back-end; users can still add listings without any problems.

I’ve gone through all troubleshooting steps, including disabling all plugins and snippets, but it didn’t make a difference. I also enabled WP debug, and the log shows:

[31-Jul-2024 15:56:05 UTC] PHP Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 20480 bytes) in /var/www/vhosts/taablo.com/httpdocs/wp-content/plugins/hivepress/includes/helpers.php on line 155

When I increase the memory limit, the entire website gets stuck on the gateway timeout page.