@Sir_John_Balman The legend not loading "correctly" is indeed due to Bootstrap v5 introducing breaking changes in the forms elements. This is the info from bootstrap's docs: <legend>s, like fieldsets, have also been restyled to be displayed as a heading of sorts. Read more about these changes here Reboot · Bootstrap v5.0
While Radzen themes are not dependent on bootstrap, the recommendation in that case would be to stick to Bootstrap v4 if you prefer the standard legend look & feel.