Stephan is right. This change caused an issue, introduced in 7.18, which might slow down the page if it contains a lot of dynamic texts / action buttons. This will be resolved in the upcoming 7.19.
If you think this is another issue in your case it might be worth filing a ticket on.
same issue with listviews. 7.18.1 loses performance in the front end, probably due to a change from dojo to react?
We had the same issue and I vaguely remember one of our team member mentioned it has to do with the appstore widget which was used in combination with Template grid.
And there is fix made for the appstore widget which will be released soon.
So, may be try to check if any of your appstore widgets is causing the issue as well.