Why does the mobile router only connect to LTE even though SIM is 5G-capable?

Zyxel_JoyLee

Even if the SIM is a 5G-capable SIM, the router may still show LTE access technology because the SIM only allows access to the mobile network; it does not guarantee that the router will register on 5G NR.

Common reasons:

1. No 5G coverage or weak 5G signal at the location
   The router may fall back to LTE if the 5G NR signal is unavailable, too weak, or unstable.
2. The router is connected in LTE-only mode
   Check whether the router’s cellular setting is configured as:
   • Auto / 5G preferred
   • 5G NSA/SA
   • LTE only
     If it is set to LTE only, it will never attach to 5G.
3. 5G NSA requires LTE anchor
   In many networks, 5G NSA still uses LTE as the anchor. Depending on the router UI/log design, it may display LTE even though 5G NR secondary cell is involved. You need to check whether there is an NR cell / 5G NR serving or secondary cell shown in the cellular status.
4. The ISP/MNO may not allow 5G access for this SIM/APN
   Some SIM cards are physically 5G-capable, but the subscription, APN, or private network profile may only permit LTE.
5. Band or network mode mismatch
   The router may not support the 5G band used by the carrier/private network, or the router may be locked to bands that do not include the local 5G NR band.

A 5G SIM does not necessarily mean the router will always register on 5G NR. The actual access technology depends on 5G coverage, router network mode, supported bands, APN/SIM provisioning, and the carrier/private network configuration. If the router only shows LTE, please first confirm with the ISP whether this SIM/APN is allowed to access 5G service at this location, and whether the router supports the required 5G bands and SA/NSA mode used by the network.