Excited to see this fix! Just wanted to add that the same behaviour can be seen when indenting a block. I'm not a SWE, but from the code in this fix I think the bug would still show itself when indenting a block.

To recreate:

• Create a block, for example #inbox
• Create new block below it (same level, not yet indented), type 'this is a test message' and press the indent button
• Note that the block gets indented, but the last word (message) is removed

@spotke Thanks for your report. indent/dedent is fixed as well.