We (Vodafone) are in the middle of rolling out some new firmware to the TC4400 cable modem (FibreX customers), expected to be completed by the end of the week. This firmware fixes a few issues, including some related to troubleshooting and stability.
There are some other threads here talking about intermittent loss of internet. Although this firmware is intended to fix some identified network issues, it's not expected to resolve everything raised here. Disconnects can be a symptom of loads of things, from wifi, to physical cabling, to network, so please continue to log faults if you're having problems so we can troubleshoot thoroughly.