Mortgage interest rates have climbed to their highest levels in two decades, which means higher payments for less home. So an olderloan known as an adjustable rate mortgage, or ARM, is making a comeback. “If you think rates are going to settle down or even go down, then you’re going to get that benefit from the ARM,” said Lee Foster, an Orlando-based sales manager with Fairway Independent Mortgage Co. The trend might cause concern among those who remember the integral role ARMs played in the Great Recession of 2008. But experts say safeguards put in after the housing crash make these loans les…