Keyboard often doesn't work for mobile Checkvist

I add so glad for m.checkvist except that quite often when trying to add items, the onscreen keyboard just doesn’t respond to input at all. Everything else on the screen works. What can I do? Thanks!

Do you have any hints how the problem could be reproduced? Does it happen on a particular list, and which device/OS do you use?

I am using an iPhone iOS version 12.1.4 (16D57). Using a give screen shortcut to a Safari page. I haven’t yet seen a pattern to why sometimes it works and sometimes not. Sometimes when it does not work the keyboard area is completely blank too.