I've just lost my work AGAIN!!!

For some reason I cannot add ideas to the Mobile Acrobat reader community, so I write here:

‌Here is an idea for your app! Fix the bug that causes your free-hand annotations to be lost every now and then! For the second time I get a "A system error has been encountered" alert and after that my last several days tof markings are LOST!!!! I've already described the bug here:

Bug report, loss of user data

but nobody seems to be paying attention. Last time it happened right after an app update. This time it was simply after a screen unlocking.

I can live with the occasional quirk, but losing my work???? Come on, guys, you can at least save the PDF before crashing!!

iPhone 6S Plus, iOS 9.1