Thanks for the excellent report.
You are correct, this is caused by the new label positioning logic. We redid that using CSS grid to solve issues we had with labels within the grid layout. If you set pbShowLabel to true with peLabelPosition on lpLeft or lpRight this also does not happen. I think we'll fix this by changing the CSS you pointed out into:
Code:
.WebControl .WebCon_Inner {
display: grid;
grid-template-areas: "control";
grid-template-columns: minmax(0, 1fr);
}
Can you test this (you can just put this in your application.css)?