Adding and removing tags simultaneously generates ongoing PHP notices

Your software
My Mautic version is: 3.1.0
My PHP version is: 7.2

Your problem
My problem is:

I previously posted this issue as a problem with Zapier / Mautic integration. It turns out after further testing it appears to be a bug with Mautic. Basically if you edit a contact (either manually or thorough Zapier) and add and remove tags at the same time this generates the type of notice below. From then on - every time that contact is updated in any way the same notice will be generated in the error log.

I’ve tested this behaviour on several instances of Mautic, different environments, with the same results.

Is this a known issue? Perhaps there is a configuration setting I’m missing?
It looks like the only way to stop this happening is to never mix add and remove tag operations.

These errors are showing in the log:

[2020-09-18 09:54:03] mautic.NOTICE: PHP Notice - Undefined offset: 1 - in file /home/site/public_html/hub/app/bundles/LeadBundle/Views/Auditlog/details.html.php - at line 62 {“mauticTemplateVars”:{“app”:"[object] (Symfony\Bundle\FrameworkBundle\Templating\GlobalVariables: {})",“event”:{“eventType”:“update”,“eventLabel”:“Zapier Automation”,“timestamp”:“2020-09-16 20:52:44”,“details”:{“stage”:[2,null],“tags”:{“added”:[“photoshop intro”,“customer”],“removed”:[“customer ld”,“photoshop intro ld”]}},“contentTemplate”:“MauticLeadBundle:Auditlog:details.html.php”},“lead”:"[object] (Mautic\LeadBundle\Entity\Lead: Mautic\LeadBundle\Entity\Lead with ID #12177)",“mauticContent”:“lead”,“mauticTemplate”:“MauticLeadBundle:Auditlog:details.html.php”,“view”:"[object] (Mautic\CoreBundle\Templating\Engine\PhpEngine: {})"},“app”:"[object] (Symfony\Bundle\FrameworkBundle\Templating\GlobalVariables: {})",“event”:{“eventType”:“update”,“eventLabel”:“Zapier Automation”,“timestamp”:“2020-09-16 20:52:44”,“details”:{“stage”:[2,null],“tags”:{“added”:[“photoshop intro”,“customer”],“removed”:[“customer ld”,“photoshop intro ld”]}},“contentTemplate”:“MauticLeadBundle:Auditlog:details.html.php”},“lead”:"[object] (Mautic\LeadBundle\Entity\Lead: Mautic\LeadBundle\Entity\Lead with ID #12177)",“mauticContent”:“lead”,“mauticTemplate”:“MauticLeadBundle:Auditlog:details.html.php”,“view”:"[object] (Mautic\CoreBundle\Templating\Engine\PhpEngine: {})",“details”:{“stage”:[2,null],“tags”:{“added”:[“photoshop intro”,“customer”],“removed”:[“customer ld”,“photoshop intro ld”]}},“type”:“update”,“text”:"",“objects”:{“stage”:[2,null],“tags”:{“added”:[“photoshop intro”,“customer”],“removed”:[“customer ld”,“photoshop intro ld”]}},“value”:{“added”:[“photoshop intro”,“customer”],“removed”:[“customer ld”,“photoshop intro ld”]},“key”:“tags”,“values”:{“added”:[“photoshop intro”,“customer”],“removed”:[“customer ld”,“photoshop intro ld”]},“field”:“tags”}

This is officially a bug: https://github.com/mautic/mautic/issues/9219#issuecomment-696398908