If wandering traders are under invisibility or it becomes day time, they don’t drink milk to clear the effect. They also don’t drink a potion if it becomes night time.
Comments 2
Cleaning up old tickets: This ticket had been set to 'Awaiting Response', but has not received a response from the reporter (~3 months+) so is being closed as Cannot Reproduce. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines which includes steps to reproduce the problem.
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You could recreate this in 1.12.1 and 1.13.0.18 beta? There is a similar issue that was fixed in 1.11 https://bugs.mojang.com/browse/MCPE-42633