You said it seems to have come on after a programming session. Is this programming session before or after the firmware update? If after the firmware update, one option to try is to go back to the previous firmware, at least just to rule out the new firmware as a root cause.
There still exists the possibility that it’s not a FW or SW issue but is a hardware issue, although still weird that it would happen to both aids simultaneously. You still have a 3 year mfg warranty so you’re not out of options. If I were you, I would try to replace the actual HAs with new ones before I would resort to the Resound Linx2 9.
If somebody else in your family or a friend has an iPhone, I would also try to pair it with another iPhone, just to rule out the issue with your iPhone. I know that you said you have the same issue with your iPad, but if it’s easy enough to get access to another iPhone, it wouldn’t hurt to try it out for another data point.
I also realize that you have a reverse slope/curve hearing loss, right? Like I mentioned before, I get a static noise (lower frequency floor noise) when I go to the directional mode. I remember the first time I mentioned this to my audi, she hypothesized that maybe it was the OPN’s Soft Speech Booster being cranked up based on my personal profile preference in this mode that is elevating the floor noise, and since I have a normal loss curve, maybe my hearing can pick up this lower frequency noise and notice it more? I’m just throwing this out there because I just realized that you have a reverse curve loss, so maybe for some reason your programming tried to boost up soft speech too much during streaming that combining that with the low frequency loss you have, the floor noise becomes noticeably loud enough for you. I don’t know, just something to check to see how the Soft Speech Booster is set during direct streaming and see if reducing it or removing it would help. Of course you want this feature to work properly for you as well, but maybe if it turns out to be the Soft Speech Booster being the root cause, Oticon can see if maybe they have a bug in their SW they can fix to resolve this issue on a permanent basis for you. Maybe it didn’t get reported to them because they don’t have enough clients with reverse curve loss that use direct streaming on iPhones.