Yes, You can't separate the WiFi bands of the EE Smart Router, unlike the EE Smart Hub. For 2.4 GHz devices that have difficulty connecting to it in its default configuration, it is best to first disable the 5 GHz band, connect the 2.4 GHz device and then reenable the 5 GHz band.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 20 Meg WBC => 2020: EE 40 Meg FTTC (no landline no.)