There was a time when OW airlines strictly (?) enforced the rule that the price of an rtw ticket must be the higher of the place it originates and the place it was being purchased, and everyone understood that to mean that the place of purchase was where the purchaser was standing, credit-card address aside.

So it was a great pleasure when airlines began ignoring that rule - perhaps in reaction to local laws in Canada and the EU. Now it's coming back.

"In the day" the way to comply with the rule was to find a TA in the origination country willing and able to sell you the ticket, and there was much discussion here about favorite TAs at favorite starting locations. The TA is your agent - "you" in essence, and there was seldom if ever a problem with the process.

Sounds like it's back to that.