I haven't been issued with July update yet, in UK, so can't comment. From what I've heard on this thread it doesn't solve the inherent problem and Samsung seem unwilling (unable?!) to address it.
This thread has been going on for some time and I would be interested to hear if anybody has more to add. There has certainly been a lot of useful information passed around here from people, notably with the absence of Samsung, perhaps unsurprisingly. (Thanks to those who have contributed.) Personally I feel a lot more in the know since seeing so many helpful comments.
Once again, I've been using a stock-based Oreo ROM from xda called Devbase 5.9 which has the latest ERG2 modem and ERG8 bootloader and battery life is better than Nougat. The latest update by Samsung should have updated the modem to erg2 which should have fixed the drain problem as is the case here. The drain for me using LTE at night with everything syncing is 1.3%/h.
I want to point out that with latest July update some countries/CSC will get latest ERG2 modem and others - old ERD6 from the first Oreo release. For example, UK/BTU and Germany/DBT firmware contain ERG2 and Nordic/NEE and Poland/XEO - old ERD6. This may be important in our case. You can check it before downloading at updato.com, after clicking at firmware there is "more info" page and the last line is "Phone G930FXXU2ERG2". PDA can be ERG2 or ERG7 which is not big deal.
@Mesho, you can flash just different modem for your model, this will stop any OTA update and will not trigger knox or official status (secure folder etc will work). The point is - broken integrity of firmware will stop OTA. Or you can try to disable system updates in developer options first.
Also I think it's a good time to ask @AntS about current status of our case. One more month passed. Do you have some news from internal bugtrack system?
For those still having issues: For me personally flashing the unbranded Dutch version (ERG2), uploaded on July 18th on SamMobile seems to have fixed the issue (there still seems to be an occasional hiccup every now and again). I had the UK version before. I flashed all 4 files and I used home_csc so I wouldn't have to reinstall everything.
Side note: Samsung has been a major p.i.t.a. lately. In reality they're no different from Apple and their crappy ways of doing business. This thread has 45 pages, and it's not over yet. And there are many others out there. It simply shouldn't be this difficult to find a solution for a problem on a device we all paid top money for. I'm definitely gonna be looking elsewhere for my next phone.