Is that usually the culprit? Tough to say...usually when people mention new apps I tap them to see what they look like, but haven't really used any. flare.pub was one I clicked on for like 15 seconds recently 🤷♂️
Its not uncommon when using your keys with new nostr apps this happens. Try using this to restore: https://metadata.nostr.com/
It seems to be “newer” clients. @elsat is it because a specific NIP is missing or any general ideas.
Op mentioned flockstr. Its difficult to know without the full multi app history. This is where something like #nostrCI would come in - automate this type of testing, and reporting. https://github.com/nostrCI Otherwise its manual sleuthing using incomplete info