@trnrmom1, My husband has had some episodes of swelling in his jaw as you have described. The only pain he has felt is when he would rub it. It comes on suddenly, usually when eating. The doctors say it ia a blocked parotid/salivary gland. They told him to suck on sour hard candy to produce more saliva that pushes out the blockage. First time this happened, we were in Wash DC for a wedding, and went to the ER. It was not easy to find a store that carried sour lemon drops, so now we keep them on hand and pack them when we travel. It does not last long.
Several more episodes over the years, have sent him to see the Ear Nose Throat specialist who said the same thing. But the doctor added that if it got infected, surgery might be an option.

His is not related to Covid, He does not have an impaired immune system.