Sharon,
Mine o2 levels leveled off 3.5-4 months after covid. I had ground glass opacities both lower lobes with covid April 2022, have asthma at baseline, reactive airways and hx of fungal pna with lung nodule. I used o2 supplement for 3 months to get around and to sleep. My high resolution ct was clean at 3 months after 2 rounds of steroids and 2 rounds of abx. Mine was clearly covid related. I am happy to say i dont have any post covid sequela.
I hope this helps