There are few factors that may affect your SMS/calls with your mobile service.
Check for service outages
Check for coverage availability
Here are also some basic troubleshooting you can perform:
Power Cycle Handset
Press and hold the handset's power button for 3-5 seconds then a reboot option should pop-out to the android/iphone's screen.
Perform Manual Network Selection
Network Selection. Check in your settings that your phone is set to automatically select a network. If your phone is already set to automatically select a network, try to manually select your mobile Network Provider to Vodafone. You may need to turn the phone off and then back on again for the change to be in effect.
For Android Phones:
Change Network Mode/Preferred Network (from 4G to 3G or vice versa)
Check that your device's network mode is set to automatic. If you have a 4G device in a 4G coverage area but you are only able to connect to 3G, make sure that 4G is switched on. You may also try switching from 4G to 3G if you’re having issues with 4G.
For Android Phones:
Choose between 4G/3G/2G Automatic, 3G/2G Automatic and 3G only and check which network would give you the best service.
Try a different handset.
If all of the above does not work, let us know of your preferred time to be contacted so we can have our Mobile support team to assist you.
Thanks for the clarification, please shoot us your best contact number and preferred time. We'll have one of our Mobile Specialists contact you for further test and investigations.
Thanks, but none of those suggestions have improved it.
As an example, I sent a text to my wife which said "waiting for connection" which she didn't receive. Then I sent one to my daughter who received it straight away.
Is there some reason why texts sent from one TPG Sim to another TPG Sim get delayed or need something to connect (the screenshot)? My daughter's text didn't need anything unique to connect/send to?