Hello and hope you are doing well.
There are tubes called 'Eustachian tubes' which connect the middle ear to the throat, this balances the air pressure in the ears. This tube can get blocked due to infections of the throat, which can give lead to a feeling of fullness in the ears. This can also result in infection of the ears. The tubes can also be blocked in Eustachian tubes dysfunction. The blockage can be intermittent. The blocked ears can be opened up by the valsalva maneuver, where air is blown into the cheeks against a closed nostrils, this sometimes helps to open up the tubes. Steam inhalations can help clear the tube. Check to see if this helps.
Hope this helped and do keep us posted.