It sounds like your firmware needs to be updated. But this would require access to the internet to download it. Do you have any access?
In the meantime, maybe changing the PowerSave setting that can interfere with wifi may help... Copy and paste the below into terminal (open with ctrl+alt+t) and then hit the enter key
sudo sed -i 's/wifi.powersave = 3/wifi.powersave = 2/' /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf
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