We've had working sessions where the moment there was an issue, the developers at BigCo said that they need to talk to someone on some team and they wrap up the meeting for the day -- even if we had just got started. It's gotten to the point where we will have project managers in the working session -- essentially babysitting -- to stop the devs from just giving up.
The amount of stonewalling I've seen is insane. We were trying to address an issue with our integration and I was told that a particular configuration on the client side was impossible, or maybe that we needed a new license, or perhaps we needed to contract to another vendor and it's going to cost half a million dollars, or whatever other excuses they could come up with.
So I asked them what product BigCo used, I looked up the documentation, I sent an email with 12 steps on how to make the configuration change, I got on a video call with my contact at BigCo (and his boss to make sure he showed up) and I literally walked him through the setting up the configuration.
I just don't understand how you get to the point where that's business as usual.