Probably you can enable 2GHz hotspot when connecting to your home network on 5Hhz. If 5GHz for hotspot, 2GHz is for wifi
In other cases, some Chinese mobile products have problems when set them up as mobile hotspots due to each regional regulation even if global models. In Japan, some correct devices try to connect at some specific part of bands(channels) which are allowed for wifi, but those incorrect devices can't accept these connections due to firmware misconfigurations or their internal radio antenna specifications