I noticed that on my first SU5 career mission, but then I did the Medevac unlock mission and that probably had a preset heavy overcast.
On the following missions it looked ok, but I couldn’t get red dot missions in freelancer. There still seems to be something going on with live weather at this time, but only in MSFS 2020: Online Services Monitoring
EDIT with more info: No missions with live weather in career mode after SU5 Update - #5 by SergeSmile