Maybe add some "Loctite" to the next set of bolts just to make sure they don't come loose as well.
Was thinking that, or more likely Gorilla Glue, but would the heat not break it up quite quickly?
Something like Loctite 638 would be fine as it has high temperature resistance.
Link: https://www.bearing-king.co.uk/bearing/loctite-638-high-strength-fast-cure-10ml/16252