I had open dome fitting with a bte air for three years and it was all good.
Then I decided to upgrade and trailed the widex with the receiver in the ear, and had the same problem as you. I were used to the normal open dome(without receiver in the ear), and with the widex it felt like my ears were somewhat blocked up. It felt like I could hear with the aid, but couldnt hear what I perceived to be my “normal” hearing. Hated using it with the phone etc. It really confused me and I think my brain just didnt want to deal with this.
After some thought I figured that it must be because my ear canals (especially the right one) is too small to deal with the receiver in the ear, and that even though its an open dome its the receiver that is blocking my hearing. In the end I got something else that works for me. Unfortunately I dont have an answer for you - I dont even know it it is possible to test to what % the receiver could be blocking out to adjust for that in the hearing aid itself.
As to your other post re speech… if you search this forum you will find that the hearing of speech is the ultimate goal of every hearing impaired person, it is also the most difficult one to realise.
“Almost like looking for the holy grail, you are not even sure it exist but you just keep on looking.”
Maybe you should keep a notebook with you, and write down specific things or situations that you have trouble with as they occur. Take that with you when you go to your Audi, it will help them understand what your problems are. Sometimes when sitting there you cant remember everything you want changed, a notebook will help with that.