[Q] G3 AOSP/CM vs Stock 4g/lte consistency - Vodafone UK

On stock based (Cloudy G3) with modem 20i/k i get 4g 90% of the time.

I am using a d855 in the UK on vodafone (also have a stock SGS5 also on vodafone connected to 4G, so its the G3)

I find any CM/AOSP based rom to connect to H and H+ and either:
1) take about 20 mins to find 4g signal or
2) find no 4g signal at all.

Ive seen the other threads which state check APN settings

• vodafone contract


• vodafone WAP contract (SGS5 uses this)


• using the CM LTE toggle in quicksettings (this is what i used to use 6 months ago to force refresh the search, seems to be a different problem now)


• used the pro version of network toggle, which isnt working at all on either rom (AOSP/CM based)

I have also tried this with the modems:

• restoring 20i modem from cloudy G3 twrp backup


• 20L


• 20T leak

i know that some things may never be as good as stock but i notice the following differences

• Stock - 4g/LTE connected instantly on boot


• aosp - network has no service for about 1 minute on reboot, then connects to h/h+


• stock - barely ever drops to h+ from 4g (we even have 4g boosters in the office as the company uses vodafone)


• aosp - once eventually connected it stays connect until the next network problem (going underground/no signal or rebooting)

Roms ive found this on over the past few days:

• Xenon HD


• BlissPop

im using additional mods (should affect signal)

• dynamic Gapps


• LCD framerate mod