DEVONthink Tab disappearing

So I have an embarrassing question, but I simply cannot figure out the answer. Occasionally when I am reading a PDF in DTTG with the iPad in Portrait orientation, the DEVONthink tab, which would allow me to scroll back to my databases, disappears. At that point, I am stuck on the PDF and until I minimize and then reopen DTTG, I cannot actually access any of my other materials. I am clearly missing some trick to bring up the sidebar. Could someone please help me locate it? Thanks a million!

You mean the back button? This seems to be an issue on iOS 13. You should. however, be able to swipe from the left edge to bring it back. Or if that isn’t what you meant would you mind and post a screenshot?

That is what I meant. but swiping from the left edge doesn’t always bring it back unfortunately.

Hmm. We’ll keep an eye on this issue that didn’t happen on iOS 12 as far as we’re aware.

This issue has been reported in iOS 13. It happens in portrait mode and the back arrow will reappear if you rotate to landscape and back.
Also, if you left swipe up at the level of the top toolbar of DEVONthink To Go, the item list should appear.