una278 wrote:
My SIM card was tested in another phone and it worked. Not an issue with cellular company . Glitch appears on new iOS 18 update
It is an issue with your cell company. They control how many seconds your phone rings before it goes to Voicemail. They also control your voicemail, it is not actually being recorded on your device. The setting for the ring time will be dependent on the IMEI number of the device and the setting is not stored on the SIM card. Putting your SIM card in another device where the IMEI number is different is not a troubleshooting step.
Call your cell provider again from the phone you want changed. The max they can do is 25 seconds. You need to specify the seconds, the number of rings makes no difference as each ring tone has their own length and the number will vary. If the ring is 5 seconds long, then you will get 5 rings before the voicemail picks up. Here is another Virgin Media support site where it also makes it clear that they have to adjust the ring time and there are many requests to have it done, so this is something they are very familiar with.
Virgin Media Support