Lichess puzzles

I've had some problems recently with puzzles disappearing for no (apparent) reason, sometimes even just after I played them (lichess.org/forum/general-chess-discussion/is-is-possible-to-find-a-puzzle-that-you-played-earlier-by-searching-on-lichess#2).
I had this problem one more time today with this one : lichess.org/training/38763. I played it, bookmarked it because I found it interesting (hopefully I also bookmarked the game to be sure I can go back to it), and then reloaded the page and got a "404 error, page not found".

I also learned that Lichess puzzles are going to change soon (lichess.org/forum/lichess-feedback/terrible-puzzle#3) and old puzzles are going to be removed. So I guess there is a link between the problem I encountered and this change.

So to all the Lichess team, @thibault, @Toadofsky and others, it's awesome if we can get new puzzles, but please don't throw out the older !! They are good and interesting too !!!

Puzzles below ID 61053*, like the one you mentioned, are not only old – they are extremely old. And they are known to contain a high percentage of bad ones. Lichess has not served them since at least February 2018, unless you specifically asked for them. Half of the posts in the forums complaining about "bad lichess tactics" turn out to be about those extremely old tactics. So I for one am glad that they are finally getting removed completely.

*source: github.com/ornicar/lila/blob/972c73764eadbef2a208a056bce2aa6fe7066250/conf/base.conf

@anonmod "Lichess has not served them since at least February 2018, unless you specifically asked for them."
Playing anonymously, I often get them. And the problem is precisely that when I specifically ask for them, I don't get them (and then I can't go back to puzzles I played).

Also about them being bad : I do a lot of puzzles and I often saw those comments about puzzles being bad, wrong and so on. Sometimes it's indeed not clear what is the best move, and it can be unpleasant to miss them, but saying they're wrong is (most of the time) incorrect : they are always about finding the best move according to Stockfish, and if there is no apparent clear best move, it forces you to think deeper, which helps you to improve, which is eventually the goal of problems ! Not getting rating points ! (If all the problems were mate in 1, we wouldn't learn much from them...)

Eventually, even if some are considered to be "bad", why not to use the rating that we can give to them to say if they are good or not in order to remove the bad ones ? That would probably be the best solution.

#1 Sorry, we're doing the best we can.

@Toadofsky Ok, sure, I understand, it's a bit caricatural though...

Maybe it would be fine if they were simply still on Lichess, but available only when you specifically ask them ? (as it seems it supposed to be but it's actually not) Anyway, I still don't understand how it is that we can have access to them so randomly : one time it works, then it disappears...

Anyway, thanks for the answer !