Minecraft Bedrock - dying whilst falling down a 1x1 shaft

Solution 1:

I originally guessed that the Speed was causing you to hit an edge block during the fall or at the bottom of it, but this was cleared up by you stating that there were no gaps and that you were taking damage while falling. I honestly can't be too sure, my guess is that it has to do with the Speed II. There is a possibility that you may be glitching into the glass with your speed, which causes the drops that kill you, as I have accidentally done that before, but that's usually when I am using an Elytra and going at high speeds. I wouldn't cross it out however, since Speed II combined with speed from falling could probably achieve a similar thing.

Try basic troubleshooting such as exiting and rejoining the world if you haven't already, and if it still persists, lower the beacon to Speed I. If it still persists, then remove Speed entirely, my assumption is that is the issue.