it means the drainage is collecting in his mouth. I'd suggest that he ask for a sputum test to see what sort of infection this is and get him on the specific antibiotic to take care of it. If he's not seeing a pulmonologist, he needs to see on and probably an infectious disease doc as well.

Check with your doctor as soon as possible.

i also have alot of heavy mucus. it fills my throat while i am sleeping and it wakes me up because my throat is filled and i can't breath. then we have a lot of coughing, spitting, gagging. i will then use a saline spray because it seems to help told my pulmonologist about it her only solution was for me to use floanase

I am struggling with similar. I had my copd hoiked to severe when an mrcp mri scan for trying to see what my gallbladder and liver are doing (still ongoing with the liver, it seems I have an autoimmune causing my antibodies to attack my own liver so non alcohol related primary biliary cirrhosis.) they found the lower lobe of my left lung is no longer inflating, but no follow up other than somebody checked I'm still using my inhalers ok! I digress. I've not had covid, 3 tests all negative so it's a lousy infectious chest infection been ongoing and laying the few other's I'm in contact with flat too. I started the copd rescue kit as soon as I knew it had gone to my chest, rescue kit already replaced. However I am coughing in my sleep still and a distinct gurgle with it. I too wake with mucus in my mouth but, it is a more healthy creamy/white than when the infection was there. I wonder if your husband is the same and coughs in his sleep? It is still best asked if you are under a team or the GP. I've asked 3 times for a phone appt with my GP as I've no energy at all still and still not had any joy. Yesterday I asked again, they rang and said they needed bloods (that's supposed to have been regular since the gastro consultant requested 2 scans urgent in May to monitor my liver, but not a single blood since the first) and usually because I'm housebound without somebody to push my wheelchair (incomplete spinal cord compression in my neck affecting all 4 limbs) the District Nurse team do any bloods at home. They said they wanted me seen by a practicioner at the surgery as well as bloods. They only did bloods, so my poor driving PA had rearranged all the care for her grandchildren mucking a working teacher and paramedic about to do so, for what could have been done at home.
Keep trying, I know they're all over stretched. Had my mucous been a more infected colour I'd have been more worried than currently am, but I would still love to feel supported with all this.