The “Eustachian” tubes connect the middle ear to the back of the throat to equalize air pressure as changes in altitude or weather fronts cause barometric pressure to change. Why it remains open to hear lying down to sleep is beyond my pay grade! However, the “Ear, Nose & Throat” Dr. should be able to correct this as an ear infection or abnormal condition may be the cause. Tinnitus added to sinus infections, medication maybe to cause this as a temporary tube issue. I use nasal spray & needy pot w/saline will flush a portion of mold, pollen, dust etc. may add to your problem. I had surgery for a deviated septum and guess what, I grows back over time, but you indicated they checked and good.
I still have tendinitis, loss of hearing after decades of car repair in dealer shops, as the never had gloves, single use ear protection or safety glasses. Things have changed. Yet I hate my sinuses as some days are horrible and other days nothing! Odd. Once the meds are gone, so may the tube noise. But go online to check side effects for each. With Severe Regional Chronic back pain, they took me off hydromorphone 8mg right to buprenorphine/Naloxone and since 2010, I get hardly any relief from pain.
Best of luck and make the best of the holidays. My wife and I decided to order a pizza for Christmas! lol!