You could move this topic to Development & Technical Discussion > Wallet Software > Mycelium
The iOS version of the wallet is subjected to this issue for quite a longer time and the devs doesn't seem to clear this.
If so, any known fixes?
There is no fixation for this issue right at the moment. Try using coinomi or other iOS wallets listed in the official bitcoin website. Bitcoin.org doesn't recommend mycelium for iOS. Try using Bitpay,BRD, Edge or coin.space wallets instead.
Recommended wallets for iOS :
https://bitcoin.org/en/wallets/mobile/ios/