Flexible hours means that it is up to yourself to manage your time. However, since other colleagues and the client have fixed schedules, this means sometimes you must be available more than 8 hours per day.
Bad management of some reply groups, in my case, as recent graduate I expected to be followed by a person. I joined a team and I was introduced the first two weeks. Then I was alone and I had to hold presentations, answer questions of the client, introduce new colleagues. I mean I was doing the activities of a senior consultant and being underpaid