Loyce is right. It happens due to receiving lots of small transactions.
Click this "Use total available minus fee" then you will get the exact figure which you will be able to send after paying regular fee.

You can also change the fee and try to send but it may take longer time to confirm.
I see you made mistake while changing the fee. You have put 150sats/byte while the regular fee was 141sats/byte. Reduce it from the regular fee and try.