Getting the latest firmware for your Zyxel NR5103E can be tricky because this high-performance 5G router is often "owned" by network providers like Tre Sweden rather than themselves.
The Zyxel NR5103E is a powerful 5G NR indoor router, but early software versions were known for specific "bugs" that users found frustrating. Updating to the latest exclusive builds often provides: zyxel nr5103e firmware update 39link39 exclusive