I am sticking my metaphorical neck out here but Romany and Traveller groups have very different ancestry.

The modern day group known nowadays as Travellers have their root in northern Ireland. James 1/6 moved a load of Scottish and English plantationists into Ireland to settle on confiscated Irish land. This would give him a load of loyalists in Ireland. The Irish that had their land stolen were forced on to the road and, eventually, became todays Travellers. This is, partly, why they believe England owes them big time. Ireland has closed off most of the off road parking by putting height restrictions in place and that is when many moved to England. They couldn't park off the roads.

The Romany families came from eastern Europe but those I have spoken to are always very vague about where they originated, especially with outsiders. Most Romany went into houses in the 60s while they had the chance but still retain many of their customs and beliefs.

Roma seem to have come to UK since the 60s, many from Romania, when the east/west borders opened and will settle into houses if they can.

I taught traveller and Romany and Roma children in England for a decade.