I am planning to use the Goals section for recording and auditing KRIs, however, I cannot save anything under the Performance tab, either in Metric of Success criteria. It just wanishes after I save. I wanted t set this, so that one of my team members are refer to it and counduct audit. I am using Enterpise version. 3.29.1 on prem.
I would start by updating to version 3.30, the goal section has been migrated and it is much better now, and the issue you are experiencing could be related to an old bug. If you are seeing the same behaviour in other sections, where the modal closes and you get a greyish screen, that is caused by an incorrect public IP configuration.