The link within the link above, is about the condition and pre-dates covid. One theory someone had (which sounds plausible) is that it's a motor "tic" (hence involuntary sudden intake of breath an involuntary tic) - possibly related to low levels of dopamine. This is interesting, because lack of Dopamine is linked to Parkinsons and I think some people had Parkinsons type symptons after Covid too (I did and had real balance problems and the shakes for about 3 weeks afterwards).
So personally I am going to try boosting dopamine (apparently this involves exercise, meditation, yoga, feelgood activities (eg interacting with a pet) and tyrosine rich foods like "chicken, almonds, apples, avocados, bananas, beets, chocolate, green leafy vegetables, green tea, lima beans, oatmeal, oranges, peas, sesame and pumpkin seeds, tomatoes, turmeric, watermelon and wheat germ."
(Taken from link below). Well I already eat most of those and interact with a pet regularly! So maybe it;s the tiredness which leads to lack of exercise, that's the trigger.
https://www.medhelp.org/posts/Respiratory-Disorders/Strange-Involuntary-Breath/show/14555
https://my.clevelandclinic.org/health/articles/22588-dopamine-deficiency