I've been experimenting so far the past day, I've been primarily in Orange County although I work in LA County. It appears that a few times it was connected to 2xCA, but the speeds have been around the 30s down. Certainly faster than standard Band 41, but not the 100 mbps that you were getting. I also forgot, but I read something awhile back where there is a limitation due to an interference with Mexico, like similar bands being used or something to that extent. I don't remember what the issue was specifically, but I thought it was competing bands with Mexico and far southern CA.
Maybe it's the Band 26 ? I almost never seen Band 26, just 41 and 25 unless I go to Los Angeles or north which I typically don't go unless needed.