Marfitalu: Unfortunately I can't help you with this. I also don't speak Thai language and I don't know any Thai checkers software where I could test this situation...
As I wrote earlier, I have never tried to play this checkers variant seriously... I only tried to find some reasonable explanation
Marfitalu: It depends on the variant of checkers you are playing. However I am not an expert for all of them... (in particular, I have never tried a serious game of Thai checkers ...)
In Turkish checkers (for example) the captured pieces are removed from the board DURING the move (possibly creating new opportunities for capturing).
However, e.g. in Czech checkers, all captured pieces are (according to the official rules) removed AFTER the whole move is completed. There exist some pretty combinations based on this rule - they are commonly called "Turkish assault"!
I guess that in Thai checkers, the second option is applied, preventing you from playing the mentioned double-jump ...
Marfitalu: The problem should be that the pieces are removed from the board after the whole move is completed and not during the move as you might need here to be able to make a double-jump ...