Running an outdated version of the Sagemcom Fast 4315 firmware can lead to several issues:
Do NOT trust third-party websites claiming to host “Fast 4315 factory firmware.” Those are often malware or incomplete dumps. Your ISP is the sole source. Sagemcom Fast 4315 Firmware
Several 2022–2023 firmware versions had a memory leak in the Wi-Fi daemon. Reboot the modem, but if it persists, call your ISP and ask to be force-updated to a build newer than 7.2.5.28 . Running an outdated version of the Sagemcom Fast