Not compatible with MariaDB 10.3.26

With a recent update to MariaDB phpBB causes high memory usage 

MariaDB 10.3.25 works just fine but the minor update to 10.3.26 causes high memory usage. 

Disabling board wide emails seems to resolve the issue for me 

I'm not sure if this is a database issue or a software issue so I thought I would report it. 

https://www.phpbb.com/community/viewtopic.php?f=661&t=2573166

https://www.phpbb.com/community/viewtopic.php?f=661&t=2573391