Phone stopped making and receiving calls

QinYang_1314494  Not sure if this is helpful........

https://help.kogan.com/s/article/Doesthisphoneworkwithmyprovider2  and also https://help.smarty.co.uk/en/articles/4670061-what-bandwidth-and-spectrum-is-available-on-smarty  This seems to  indicate that your phone should work in the mid band, but not in Smarty's low band maybe?

I also found this quote (and similar repeated often) : At a high level, low-bands have greater coverage but lower speeds, mid-bands have a balance of coverage and speed, and high-bands have higher speeds but less coverage. In addition, each band presents opportunities for a service provider to balance between frequency, coverage, quality, latency, and reliability 

Is it possible that the phone does not like the UK frequency bands? I'm assuming that yours is Australian here, so hope I'm not wasting your time.

please read my three replies in reversed order

also, under 'sim cards', both 'sim slot 1: smarty' and 'mobile data: smarty' are in black and i can choose to switch them off; but other items are all in grey: 'calls: smarty', 'sms messages: smarty', 'allow to access mobile network during calling (switched off)'. why are they in grey? are they set as default? 

many thanks for helping me pursue this issue. i checked the settings on my phone (a cheap yet robust kogan model of agora xi), its 'mobile network' indicates smarty; its 'preferred network type' shows 4g; and its APN shows: 3 (mob.asm.net). its 'sim cards' shows 'sim slot 1: smarty' (followed by my phone number); 'sim slot 2: sim empty'; and 'mobile data: smarty' (which is correct, since smarty data works well on my phone). the mistery continues ...

i would think it is a problem of compatibility: my smarty sim works on another phone, my phone supports calling with other sim cards (vodafone and giffgaff); and smarty sim card used to worke well on my phone, now they do not any more. 

Hi QinYang_1314494, 

Sorry to hear about your problem.

Does you phone support 4G calling, and is it enabled in your handset settings?

If you have two SIM slots, you can try putting the SIM in the other slot. Sometimes VOLTE doesn't work if there isn't a SIM in Slot 1.

You can check if your phone is compatible with 4G-VOLTE here.

Thanks,

YulianK

QinYang_1314494  So, if the sim works well in another phone, surely it must be a problem with your current phone, don't you agree?

it worked well on another phone. it is good to confirm that i have exhausted possible cures (except a major reset of phone). i have tried the web chat bot a few times, but personally i think it's a waste of time. ai can't replace real humans yet! thanks a lot indeed!

QinYang_1314494  Fair enough then. I do wonder whether moving the sim between phone and router is not really good for it.

Further check - can you try the sim in another phone?

Failing that, I think you will need to have a web chat with Smarty Support so that they can check everything.  https://smarty.co.uk/contact