Alignment slowly renders with string search

When I do a string search in my multiple sequence alignment, it lags heavily when I want to scroll through alignment with the window open. I accidentally fixed when I moved the search window to the side, where it doesn't overlap with the alignment anymore. Suddenly it scrolls through much faster without any delay. Looks like it is struggling to render the alignment view with other windows sitting above it.

See video footage to help explain. The first footage shows the slow rendering, and the second footage shows the accidental fix where it renders faster.