Welcome to Manjaro!
Please read this:
Not many if you power down using the power button, so use the above first and then Please read this:
https://archived.forum.manjaro.org/t/how-to-provide-good-information-in-your-posts/37102
and post some more information so we can see what’s really going on. Now we know the symptom of the disease, but we need some more probing to know where the origin lies…
An inxi --admin --verbosity=7 --filter --no-host --width would be the minimum required information… (Personally Identifiable Information like serial numbers and MAC addresses will be filtered out by the above command)
P.S. If you enter a bit more details in your profile, we can also see which Desktop Environment you’re using, which CPU/GPU you have, …