Well he never actually gabe up his claim from the 1st time, he just reaffirmed it. Trust me, he will act on England but I dont want to spoil much about that.
It OTL Scotland actually started to feel like the lesser member of the Auld Alliance and grew to resent that. Then as the Burgundian civil war opened Edward was using Neutrality so Jame chose to act and invade on a very weak claim. Edward eventually got involved to help the French and James fled back to Scotland, still claiming the French throne even though on faulty grounds. The French and English fought etc. etc.
He has no base to his claim but 1/2 of France was in turmoil and wanted a monarch (as Edward was at the time rescuing because of Queen Mary) and James wanted land so he accepted, failed, fled, and claimed the throne. Its kind've like how England claimed the French throne until George III, i believe.
Except that the Kings of England do have a claim - via Edward III's mother
By primogeniture, Edward III and his successors are the rightful kings of France.
James . . . pulled this out of his ass.