[Galaxy Note 4 Android Development (Snapdragon)] Black Shade:
I've used this ROM for two months, since the 5.8.0 release. Google Assistant has always been there, just long press the home button and it works without any mods or settings. The data problem is strictly related to you Modem, make sure you're on the latest version (DQA1). For me everything works fine, if it's not an hardware issue you will solve it like I said.

---------- Post added at 03:59 PM ---------- Previous post was at 03:56 PM ----------

The problem is related to the modem, usually it doesn't matter if you clean flash it or not (you may have performance issues or graphical glitches though, that's why a clean flash is recommended). It takes 5 minutes to update modem and bootloader (DQA1) and you'll immediately see improvements

---------- Post added at 04:13 PM ---------- Previous post was at 03:59 PM ----------

The problem with file manager has been there since the first release, I think there's not much we can do about it. It's not a big deal though, Solid Explorer is the best option and works just fine. If you want something simpler, you can download the Lenovo File Manager from the Moto G4 Ported Apps thread, it's a pretty essential but decent option.

I'm using HTC Camera as default camera app and it's a great option, I don't have any issues with the flash. I got it from APK Mirror, it's an older version since the newest ones don't work anymore on non-HTC devices. If you're interested, I'll upload it to Google Drive and share a link

---------- Post added at 04:17 PM ---------- Previous post was at 04:13 PM ----------

Make sure Google Phone is your default phone app (sometimes, for some reason, it doesn't do that automatically) and also assign all the needed permissions to the phone app, it should work. If you didn't install it via Gapps package, also try setting Google Phone as a System app.

---------- Post added at 04:26 PM ---------- Previous post was at 04:17 PM ----------

I didn't notice any random reboots, if you are sure you have the latest modem and bootloader and you did a clean install, then make sure you don't have any particular apps running (in past, I had issues with L Speed and some camera apps) and also check if all the settings in Kernel Adiutor are fine.

The file manager problem has been there since the first release, I don't think there's a way to fix it. It's not a big deal since you can replace it with better app such as Solid Explorer, or maybe Lenovo File Manager if you want to keep things simple.

---------- Post added at 04:36 PM ---------- Previous post was at 04:26 PM ----------

Some people do, some others don't. I have no idea about what this depends on, mine is fine. I had issues with L Speed a couple months ago, and I don't use it anymore. I also had some camera apps causing reboots. If you have latest bootloader and modem, and you clean flashed the ROM, then checking you apps is the only solution I see.

Edit: I've heard about someone who had the same issue with another ROM, he solved by setting Google Phone ad default calling app and making sure all permissions have been granted for this app. I don't think it's the cause for that, but you may want to check if everything is fine