I'm having this issue on 1.14.3, with a different context than what I've seen in the other comments.
I had one armor smith in the village, and one blast furnace, then I stopped seeing him around. A new armor smith appeared, presumably to take his place. Now the old armor smith is back (same trades/experience), but the trade screen is doing the flash bug. There is still only one blast furnace in the village so maybe part of the bug is from two villagers sharing the same job site?
I would be curious to see if anyone else has more buggy employed villagers than relevant job blocks.
I'm having this issue on 1.14.3, with a different context than what I've seen in the other comments.
I had one armor smith in the village, and one blast furnace, then I stopped seeing him around. A new armor smith appeared, presumably to take his place. Now the old armor smith is back (same trades/experience), but the trade screen is doing the flash bug. There is still only one blast furnace in the village so maybe part of the bug is from two villagers sharing the same job site?
I would be curious to see if anyone else has more buggy employed villagers than relevant job blocks.