Thanks Jerry for your report, I don't know why it happens that
problem on my hand, possibly because of JAWS not fully updated but
this is just my supposing.
A friend of mine said that he doesn't have this mode yet, he's
using NVDA as his primary screen reader but I don't think this can
have anything to do. My theory is, split view is gradually rolling
out for users, like some Whatsapp features such as calls.