@darklightxi@lemmy.world, I see there's an open issue for this, but wanted to add my details here to try to help pin the problem down.
Unlike Eager Eagle, I've run into this problem using HeliBoard as well (and checked with standard Gboard too to be sure, also OpenBoard). In my experience of the issue I suspect it may be related to the UI not responding to the display of the virtual keyboard, which is also an issue that appears when trying to search for posts in specific communities. In both instances UI elements, specifically text input fields, are partially or completely covered by the appearance of the keyboard.
I think some of the difficulty in replicating this may be related to running tests on higher display resolutions (and/or devices with higher display resolutions), and/or with some text/interface settings set to smaller scales instead of default or larger scales. Regardless, inasmuch as possible the UI would benefit from adjustments to be more responsive to the display of virtual keyboards as well as, to a lesser degree, the display of the bottom navigation bar/buttons (for those that don't/can't use gesture navigation depending on OS version).
All that said, really appreciate the app! It's great for browsing, especially with the keyword filter without having to sign-in. Thanks a ton for all the effort from all of those involved!