is it Phoenix, not Terra Classic? then we updated its minimum gas price (which has been changed recently via its governance) yesterday

seems like Terra Classic has a different fee system, taking sending amount * tax into consideration when calculating fees. so you need to set:

keplr.defaultOptions = {sign: {preferNoSetFee:true}}

and calculate fees on your frontend and request for signature to Keplr.

I believe the validators have upped their fee for IBC's, to combat spam. I suspect that there is some config in Keplr that needs updating, as I have been able to succeed using Leap wallet

And this was a second attempt when I tried to force the fee higher:

This was my first attempt, when I specified "auto" for the fee: