Strange effect with Typewriter smart field

In my just renewed website with Sparkle,, I saw a strange effect using the smart field Typewriter. I placed three Typewriter fields in one textbox below each other on the homepage. It looks and works perfectly in the preview, but shows a white line (up) at the end in Firefox and Safari on a Mini (El Capitan) and on Linux Mint 20 on a HP it is the same in Chromium and Firefox. Strange enough on my iMac 27 with Big Sur it’s OK in Firefox and Safari.
Can anyone please give me a tip where it goes wrong?

I can’t seem to reproduce the problem. Please email us the project file (just the home page is ok) at, and exact browser versions for the browsers where the issue shows.

Duncan, thank you very much for the solution you gave me: without knowing I suppose I ticked the scrollable function in connection with the Typewriter smart field.
Now it works perfectly!
Very much appreciated!

When someone brings a problem to this forum and you then have them send you a project file, it would greatly enhance this forum if you publish the solution here. May reduce your workload too by preventing reposting the same problem by another Sparkle user.

Of course, and I already did in my earlier reply and thank you to Duncan. His solution here in full:

“Not actually a typewriter issue, you have set the text containing the typewriters to scrollable:
(See button in the right panel)
This causes a scrollbar placeholder to be shown on Macs that have a wheel-based mouse, and on all windows or linux computers that don’t hide scrollbars.”