Sustained Foot Numbness in one foot for 2 weeks

Hi there, first time marathon training here. I’m a 41/Male in decent shape and following a 18 week program with 2 easy runs, a workout, rest days, and a long run per week. Everything has been going well until 2 weeks ago when I started experiencing numbness in my right calf going down into my right foot. It does NOT go away, it’s contestant uncomfortableness. I have tried rest, stretching, and massage. I am running in properly sized Hoka Clifton 9’s. I’m not in pain, just uncomfortable. I do have a pre-existing old back injury with herniated disks L4, L5, S1 but have never had any significant Sciatica from it. Just looking to see if anyone has had anything similar. All the research that I am doing shows numbness while running, I can’t find anyone specifically saying that the numbness does not go away after the run, but just remains there constantly.