For the past month or two I've been getting tons of errors like this in nostr:nprofile1qqstxwlea9ah3u6kjjszu6a7lrnhqkfh8eptp2z6v0e9558tlkkl2rgpz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsz9mhwden5te0wfjkccte9ec8y6tdv9kzumn9wshszxnhwden5te0wfjkccte9ekkjmnfvf5hguewvdshx6p07xr4s5 with the mint.minibits.cash mint:

```
message":"The mint could not return signatures necessary for this transaction","params":{"message":"outputs have already been signed before."
```

Sometimes quitting the app and trying again fixes it, which seems really weird to me. 
Anyone have any ideas?