Visible is truly unlimited on everything including hotspot, but hotspot is limited to 5Mbps speeds though. The base plan is deprioritized so speeds are location dependent, so depending on where you go you might find data speed super slow and possibly unusable if there is high traffic on the towers you get the signal from to speeds of 200Mbps(speed is capped at this speed on base plan).
Your phone likely is not a US model or meant for the US which may be one reason it shows not compatible. Another reason is that Visible IMEI database is limited when it comes to Android phones. You also may run into issues trying to get a SIM card for your phone, or actually getting a credit card from outside the US to work with their system.
There are a number of MVNO's in the US but I have no clue what to recommend, I know of a few but don't know what they offer sush as Mint, US Mobile, Google Fi, Cricket to name a few.
If you think Visible will work for you and if you are visiting a person in the US and they have a compatible phone, are willing to order and pay for a month, then activate it with a new number you could possible transfer it to your phone and see if it will work.
