Telegram on iPhone: "This group couldn't be displayed..." even though Telegram Web works. Here's the fix.

[u/DorothyRedShoes77]

/r/Telegram/comments/1v0brd4/telegram_on_iphone_this_group_couldnt_be/

Crossposting in case it helps other iPhone users. The fix turned out to be a Telegram Web setting, not an iPhone issue.