I am having an issue with the tab strip customizer. I have to use HTML in order to create a new line and I have a tab strip with 8 tabs all with html. It takes me up to a few minutes to make a single modification and realized that this behavior started when I begun adding html. If I create a tab without html, response times are normal.
I cannot duplicate this behavior in 7.6.3. Can you provide me with an example of what you are including in your tab strip Display Name that is causing this slow down?