Old known words appearing as Blue again in new imported lesson?

Occasionally I find a lesson where old known words show up as blue again.
E.g. I have two lessons open at the moment, in one of them the known words are correctly un-highlighted,
but in the other, those same words are highlighted blue.

It’s not a show-stopper, I guess I can ignore them, but wondered if this was a known issue and if there was a workaround?

Thanks

If wrongly spelled words have been corrected by the lesson creator, they show up blue if those corrected words are new for you.

Thanks, but I think they’re correct. e.g. the Swedish word ‘men’ = English ‘but’; this kind of word has been in almost every lesson. Today I created 2 lessons that used it, one lesson shows them correctly un-highlighted, the other lesson shows them blue. Identical spelling.

@Steve555 - Sounds like a strange issue. Does refreshing the page help? Also, I wonder if reimporting the same lesson text will yield the same result.

-ignore me -

@ maths Why should we?