So basically, I tried to withdraw to a Segwit/bech32 address that starts with bcXXXXX... - It prompted me to use a "profile address" which I now realize was the legacy withdrawal address I used in the past, but it was late at night and didn't click with me that I needed to change withdraw address on profile.
The same thing happened to others too (use of a bech address, use of a different crypto address, etc.) and if I remember correctly, using an address to withdraw that is not supported by freebtc causes the withdrawal to be canceled automatically.
It is not possible for users to cancel a withdrawal after it has "entered processing" so the only thing you can do is wait for it to be canceled on its own.