The public IP address is dynamically allocated by the TalkTalk Network Edge router that your service connects to. So, until something causes the network connection to change, the IP address usually remains the same. It's not usual to see 'random' changes.
It's recommended not to switch off a fibre service router and switch back on straight away as the Strategic Dynamic Line Management (SDLM) for FTTC service can interpret this as a fault and may lower the speed temporarily.
If you wish to reboot a fibre service router then switch off for say 30 minutes to make sure a new reporting session is started. This shouldn't then cause an SDLM issue.
A 30 minute router reboot may or may not cause a new IP address to be dynamically allocated.
Was there a reason for asking? Has your service been disconnecting recently? Have you run a Service Status Check?
I prefer to have a static IP address and was just wondering if simply keeping the router on would do it? You mention something causing the network connection to change - what else would cause a network change? .. other than switching the router off/on. Thanks.
Keeping the router on 24/7 is recommended. It would help to keep the IP address the same. But it's still a dynamically allocated IP address.
Most telephone exchanges have diverse fibre paths incoming. Those fibre paths connect to different Edge routers on the TalkTalk network. There's no guarantee that the network Edge Router issuing the IP address will always be the same.