OK, I have hosted solutions. The server is in a building down the street, but we're on the same domain as the server.
The slowness/coffee-cup shows up when you open a solution that requires a password and is authenticated using Filemaker accounts (not externally).
Once the solution is open, and I do a ctrl+shift+D (Manage Database), I'll see it again and have to wait sometimes 5-10 seconds before Manage Database is open. Same for Manage Layouts. Sometimes I see it when I try to open Script Workspace.
There's an older solution which I have set up to log in using external authentication (except when the file is opened using (Shift+Open). On this file, it can be opened with a double-click which works very fast, and opens the file very quickly. But I have some accounts set up to use a different privilege set that requires the Shift+Open and those accounts authenticate to the Local Filemaker file. Those process slowly. Like 20 seconds to get to the first layout vs practically immediately when the user just double-clicks to open (which then reverts to the external authentication).
I'm stumped at what I need to do to make these open quickly, and why the ones that authenticate using Filemaker accounts are lagging.
PS- I'm not at all a network guy, so anything involving testing and troubleshooting the network will need to be sort of explained in dummy-detail.