I live in Koh Samui with a Non Immigrant O Visa with multiple entry. Paper work glitch means mine didn’t get renewed for the second year but the rest of my family’s did. I had two trips already planes that gave me enough time on Visa exempt to get back to the US so I could apply from there. Got in no problem after my 1st trip. On my second trip before returning g home I was pulled from the line and questioned for 30 minutes. They were not goi g to let me in. I showed them that I had a return flight to the US and they finally let me in. People that abuse the system make it more difficult for those of us that have proper Visas, but end up in my position. Tell your kids to get a proper Visa. They can get an Education Visa for Muy Thai.
do you speak with an accent? Just guessing as to what the reason could be. If you don’t have any type of accent I’m not sure what the reasoning would be.
The airline at your departure destination is who would ask you. We booth throw away train ticks for $12 each our last trip because we didn’t know when we were leaving. Check with your airline to see if train travel is acceptable. If you do get asked you will have to buy a return ticket to board and that can be very expensive. You could gamble and probably won’t be asked, buy you just never know.
I think the point is, you may make it in 100 times, then the next time you get asked. Like you, I have come into Thailand many times without issue. It’s always a gamble!