On my MacBook Pro (13-inch, M1, 2020) with macOS Big Sur 11.4, my second screen works fine for approximately 2 hours. After those 2 hours, it turns off each 4-5 minutes for a few seconds.
I tried to change HDMI, change TnB hub, uncheck "True Tone" as mentioned here to no avail.
I have tested 2 screens (Lenovo L27i-28 and iiyame 23.8").
This happened only with my MacBook Pro on Big Sur.
Any help will be appreciated
EDIT :
I note that it happends during periods of high outdoor temperatures (35° C, 95° F) because when i place an electric fan in my desk near my MacBook it works fine.
My thunderbolt port is 48-49° C (120° F) and connected with hub.
Have any of you already had this problem ?