Quick update: I again compared the screenshots I originally have taken with the current data and the wages did not raise. It does only take some time until the visual bug isn't seen anymore (-> continuous training does not revert the original value and it will still keep getting higher). You'll have to wait some time und abstain from training the player(s), till the visual "bug" does not occure.

What I do not know is, if the temporarily raised wages do have an impact on your finances. I don't think so, but it could/ or should be checken in the future.

Best,
Alex