If you tighten the truss rod you are removing relief and counteracting the increased tension of the strings.
Chromes aren’t a huge tension change from TIs in reality - after installing the action had increased by no more than a mm (after having time to settle) Adding a bit of tension to the rod to remove the added relief from the new strings should have been fine:
Righty tighty, lefty loosey.
The string action did indeed come done by about a mm - but 15/20 mins later, massive cracking noise and there you go..
Funnily enough the action hasn’t changed a jot..