Question about Acer Hotspot Connect M5

In addition to the 2.4 GHz WLAN, a 5 GHz WLAN can be activated, which is logically faster. Now, however, the 5GHz WLAN switches itself off every now and then for a short time, so that all connected devices connect to the 2.4 network. It wouldn't be a big deal if the VPN connection in the HO wasn't interrupted every time because of this. Does anyone have the same problem or know the cause?