I did a signal graph and saw signs of 5G (narrow signal spikes) all the way up to 3.8 GHz.The commercial C-band users are also having a difficult time with 5G interference and since its a multi tiered rollout over time you had to buy a specific filter or filtered LNB at the start of this mess then when the next tier is on air throw away your new filter or LNB and buy another and so on until the final 5G stuff is on air. Then maybe the last and final version of filters or LNBs will cover all the interference. Maybe, maybe not depending on how far away you have 5G towers.
It could be that some of you have filters or LNBs that were adequate for an earlier 5G rollout and now they are letting newer 5G freqs through and you need a newer version. If you were lucky enough to have registered your C-band receive only dish with the FCC then they will pay $$ towards your filter or LNB upgrades. For most of us its $$ down the toilet.
From reading various websites, it sounds like the move up to 4.0 GHz will be in about 1 year.
But if you live outside of the "top 46 markets" you probably won't need a filter.