There is - unfortunately - the possibility that the LD was not eradicated from your body & you are having a relapse. OR - you have been re-infected. Neither of those options sound like fun - but I deal with both, myself.
Are you under the care of a LLMD? If so, have you talked with him/her about this?
IMHO - there are & will always will be tests that 'need' to be run, but a clinical dx by a knowledgable LLMD seems to be the most accurate in the end.~
"Conditions": Lyme Disease (neuro, gastro, bone, brain, muscle, hearing involved), STARI, RMSF, Hashimoto's Thyroiditis, Lyme Arthritis, Neuro LD, FM, Chronic/acute EBV, IBS-C, Diverticulosis (& "itis") & now Lyme arthritis (?).