Hi,
You may try disable all non BuddyPress plugin and change your WP theme to default theme for temporary.
Check site to see if issue still exists. If issue goes away after deactivating other plugins and switching theme then this means that either the theme or one of the plugins was conflicting with BuddyPress. If it turns out to be a plugin/theme conflict, then you need to activate the plugins/theme one by one until you find the plugin/theme that causes the issue to come back.
If the issue still exists then it is not a plugin or theme conflict. And do these things
1. If you have a custom code in bp-custom.php, please remove it for temporary
2. Make sure to use the latest version of BuddyPress
3. Check your PHP version, and upgrade it to minimum 7.4 version.
PS: Backup your website first before do those steps!