Hi Tommi,
There was indeed a bug with the application I use for staking rewards payouts, Crunch. The bug caused looped failed transactions with no output to Matrix. The bug was particular to my mode of payout (grouped) combined with the volume of payouts that the bot does. While most individuals may only have 1 or 2 payouts, I'm issuing larger volumes.
I engaged Turbo on the matter and he was extremely helpful with rolling out a few patches to help remedy the issue. While fixes were being tested I issued smaller top-ups (of my own) to minimize exposure and to keep the service running.
I am satisfied that the bug is addressed but given the point you've raised I suggested (to Turbo) a further measure. He'll add in a feature of Crunch that would stop transactions if a user defined threshold is exceeded with 24hrs. For example we can set the threshold to 10 DOT and the most that would be spent in a day is 10 DOT.
Thank you for your feedback,
Will
As a validator operator, I rely on this bot for automated payouts. Thanks for setting this up, Will!