The MediaTek Wi-Fi 6 MT7921 Wireless LAN Card and driver have an energy conserving feature that turns off the WiFi transmitter when not needed. That's why you see the WiFi signal/symbol diminish. The feature was developed for Windows 10 message "packets". Windows 11 may use the message "packets" differently/for other purposes. The work-around is to disable the energy saving feature.Go to Device Manager/Network Adapters/MediaTek Wi-Fi 6 MT7921 Wireless LAN Card properties/advanced:Select the energy saving feature, such as "Wake on Magic Packet" : set to "disable". Restart the laptop.
The problem has been observed on various laptops utilizing the AMD chipset, specifically: The MediaTek Wi-Fi 6 MT7921 Wireless LAN Card and driver appear connected but doesn't work. Resetting, disconnecting and reconnecting the wireless adapter  works for a while. 
AMD WiFi fails, disconnects, Network Adapter MediaTek WiFi 6 MT7921 Wireless LAN