You are probably aware of this, but did you send the text using the +12225558888 format? Most of what I have read about 3-UK is positive. Also, the sims are already data and roaming active. So, not sure why whatsapp did not work for you. As long as you have the correct APN. Also, You may want to to go into the phones menu and make sure allow roaming is selected.

Three UK changes prices for roaming in USA
 

I received a SMS from ThreeUK this morning.
It said "Wecome to the USA" where it has always been since activated in early June[?].
It was titled "Rate Advice".
It would appear that the rates have changed.
{call, text, data} 3.3p, 1.3p, 3.3p/MB [old 3p, 2, 1p/MB]


The newest PAYG_Price_Guide_191017.pdf does not seem to reflect these rates.

Well, I went to Amman, Jordan, but had a layover in Vienna as my flight got canceled. Had a friend there and we talked and messaged several times and the 3 sim worked perfectly. Bossman, I think you were right I might of have roaming turned off. Very pleased with the sim card.