I could quote a fixed price for some work, and they'd readily accept my rates. But if I then would try to leave after the amount of time the work actually took me, they'd question whether or not I was actually doing the job properly.

So I quoted even higher on the expectation that 1) I'd have to sit in a chair in their office 8 hours a day and so couldn't do other work elsewhere and needed to be compensated extra for that inconvenience, 2) I'd be bored out of my mind trying to fill the rest of the time I was there.

Never a question raised.

It was frustrating. Especially one job where I as stuck for 3 weeks on a machine with no internet connection doing a job I could easily finish with 2 hours every day. Whenever possible I'd work remotely.