Please also see this post here with a Script solution. This is a Long Standing problem in XFCE (Even noting that one users comment: "This bug has been annoying me for years. I suspect there are prehistoric cave markings somewhere complaining about it ")
This is not a fix... But the only other thing I know of (in XFCE) is to not suspend on lid close (thereby circumventing the failure to resume from suspend on lid opening)
If you look in /etc/systemd/logind.conf there may be a line that looks like HandleLidSwitch=ignore with a hashtag in front of it commenting it out. Remove the hashtag to uncomment it. If it is not present, add the line.
If you look in /etc/UPower/UPower.conf there may be a line for IgnoreLid=true - follow the same procedure as above.