Wallet 3.x Withdrawal fee in BTC keep adding up - Not able to withdraw STX

I have stored STX on Blockstack 3.x wallet. When we try to send it is showing need BTC as fee. When we add balance shown then again asking more to transfer. Transferred again now again showing to add more BTC.

This leads to suspect project/wallet credibility. This is suppose to use STX itself as fees and withdraw or stick it some fees shown initially. It can’t keep asking add more and more.