I have family in the CHP who have confirmed that dickheaded officers absolutely can and will do that as you are an obstruction to traffic if going too much slower than surrounding traffic.
They had some nasty things to say about people like that, but it happens
You’re not going to get a ticket for going the speed limit
“22400. (a) No person shall drive upon a highway at such a slow speed as to impede or block the normal and reasonable movement of traffic unless the reduced speed is necessary for safe operation, because of a grade, or in compliance with law.”
Who to trust: some rando on the Internet just insisting something is true or the people who work for the department that issues those tickets? Hard pick, honestly.
Wow, look at all these sources disagreeing with you! To be fair they were really hard to find_