Y'all might want to take a look at what I posted a little while ago over here:
https://groups.google.com/g/video-downloadhelper-q-and-a/c/jRjBH5lDctw
It's basically the same advice as what Jérôme gave above but with some more detail. The
topic over there is the Hotmart web site but the same reasoning might -- I say, MIGHT --
apply to teachable. Maybe. But you won't know until you try it. It's a good idea in
any case to get on the latest versions of VDH & the CoApp on general principles. There's
no sense in hitting bugs that have already been solved. The latest release cures a lot
of problems. You owe it to yourself to try it. Even if you don't normally use Firefox,
try it anyway, even without a VDH license. See if it works. Maybe you'll decide to
start using Firefox instead of another browser.