Pieces disappear in tactics puzzles (bug report?)

I have been seeing this error for a while.
I believe this issue is not posted in the Lichess forum yet.

How to reproduce the error:
1. Go to puzzles (lichess.org/training)
2. Click on the puzzle ID link (the ID shown under the chessboard)
3. Then I see an empty board without pieces.

I am using Safari, iOS (15.2.1) on iPad Air.
I checked that this error appears in different environments as well:
- Firefox, iOS (15.2.1) on iPad Air.
- Google Chrome, iOS (15.2.1) on iPad Air.
- Safari, iOS (15.2.1) on iPhone SE

Can you reproduce this error on your device?

This problem is not happening with everyone, because it's not happening with me. Just refresh when you see that error and it might fix the problem.

Not happening with me too. Maybe view it on Android? Or refresh might also fix the error.

just update to newer ios

Thank you for your replies.
With the devices I mentioned above, refreshing and clearing cache data didn't solve the issue.

Update: I tried with the safari of macOS Monterey(12.1), and the issue did not reproduce.
(Unfortunately I don't have Android devices.)
As far as I know, this is the issue with iOS.

I will try updating iOS.

I updated the iOS of my iPad and iPhone to 15.3.1, and it solved the issue.

I’m a bit surprised that Lichess is this version sensitive.
Or perhaps my devices (both iPhone and iPad) had some problems in common, and it happened to be solved with the OS update?

Anyway, thank you for your comments.

I often play puzzle streak in safari on my way to work, eliminating the factor of losing my internet connection (I don't sign in as I'm on my work phone). What I have found time and again recently is that it works until I get a puzzle wrong, at which point if I tap on New Streak I get a board with no kings (!) or, more often, a board with no pieces at all (squares will be yellow to show me which piece moved, but without knowing what the piece was or where anything else is it would be hard to attempt such a puzzle). It occurs to me as I write this that it might be blind mode, which might be useful if you're playing a game from go to whoa but, again, solving a puzzle that jumps out at you like that when you can't see the pieces can't be easy.

To get round this I find it is necessary to go to the home page, and then click on puzzle streak again. So I found a workaround, but still it would be better for us commuters if the bug were fixed.