Am posting this here in case someone else has had a similar problem.
On a Surface Pro, i7 discreet GPU, 16g RAM, Win10 that has been running sketchup files perfectly, since a recent windows update the SU files run fine but opening (double clicking) components and groups causes the cursor to change to the circular loading icon and take several seconds to open the group/component.
Have you looked (by date) for files/updates which have been installed onto your system.
You can usually track down some information on what they entail. . . and doing so might provide a clue as to what’s at play here.
Might be possible to uninstall the offending update. . . just look for the one with beady eyes, and a slight limp in it’s stride, then show him the exit.