ACCESS POINT NAMES - worth tweaking mine for some improvements? (Samsung S23)

Hi. Over the last couple of days, mobile data signal is flickering to none existence, and signal is very poor.

I rely completely on using mobile data as I have no WiFi at home.

All was fine until I did a Samsung update on Sunday and now the phone is behaving like it's on 2g mostly, or 3g at the very best.

I'm stabbing in the dark here, as the update can't be rolled back, but I wondered if editing phone access point names could help?

I can see that Smarty's recommended settings are these:

Android 
General APN settings (Android):

Name: 3
APN: mob.asm.net
User name: [leave this field blank]
Password: [leave this field blank]
MMSC: http://mms.um.three.co.uk:10021/mmsc
MMS proxy: mms.three.co.uk
MMS port: 8799
APN type: [leave this field blank]

My current settings are the same except for:

Name: Smarty internet

APN type: default.supl.mms.xcap

Plus I have a whole host of others in the settings list that can be tweaked, but Smarty doesn't state them. 

I've done the usual.. restarted phone / switched in and out of flight mode / and wiped the cache partition after the update.

Any thoughts on how improve things even just a little somehow please?

Thank you