will my pixel 3a still work when smarty switch of 3g getting different views on this

You are welcome ChrisEdg_963607 
Unfortunately, it is little known that mobile phones are also constrained by the software updates it receives and specifically where they come from, especially when it comes to certain features that require enabling 😤.
When we talk about phones being 'unlocked' most people will assume they will have a 'fully working' phone when switching between providers (which is true to a certain extent) but when a single network controls the software updates that are necessary for the full use of a device, and you don't know that is the case, then it causes a serious headache unless you have the time to do the research.
There certainly needs to be more information 'out there' as there are too many people worried as their phones don't work once 3G is turned off (even though they have a VoLTE compatible handset) but they don't know what the problem is.
I'm trying my best to help spread the word!

 

Hi henrylo_2149097  ChrisEdg_963607 👋
Although your phone is set to '4G/3G recommended' it will only connect to the relevant signal that is available from these choices.
You are getting these messages from SMARTY as they monitor the type of signal your phone is using and in this case it is 3G.
WelshPaul is correct in that you need 'LTE' in the connection type to be able to connect to VoLTE (4G).
Even though you have a Pixel 3a, this post may help to clear up the confusion as to why your handset is not connecting to or doesn't have the option to connect to VoLTE.....
https://community.smarty.co.uk/t5/chats-hacks/can-t-make-receive-calls-not-necessarily-a-network-problem/m-p/28408#M18064

Please use Google (other search engines are available) to help in determining the information you need if you wish to Flash you phone as this post is based on a Samsung Galaxy.
Even though MSF suggests 'Thing is, if the worst does happen, you can pick up a working phone fairly quickly these days (depending what you want)' you CAN NOT guarantee that you won't have the same problem unless the newer phone is 'Flashed' to unbranded software (if the control of the software updates is the problem).
Good luck x

You need to make sure the device supports VoLTE, not 4G. If you have 4G but no VoLTE then you won't be able to make or receive calls once 3G is turned off.

I do think thats good enough from smarty, they need to clarify whether the google pixel 3a will still work post 9th September/3G switch off or not.  People rely on their phones and if it suddenly stops working then we need to know for definte before that happens.

henrylo_2149097 A quick search suggests that it works on 4G - are you seeing 4G on the screen at times?