Not sure if this is the right place or if there is already a thread for it, but I couldn't find it. So moderators, feel free to move if you think it's appropriate.

First off, I am not looking for advice, as "it's gonna be fine", I am sure. It is just for your amusement. It spans two airlines and their IT systems, but I am posting it here since Delta are who issued my tickets.

I will be on a flight from Europe to the US soon, sold and mostly operated by Delta, with the first leg being a KLM codeshare. When I booked the flight, the TATL segment was in PS, so Delta told me that I can check 2 bags, weighing up to 23 kg/50 lbs each. Makes sense. Loading the trip in the KLM app, it shows only 1 checked bag included, with the same weight limits applying. I contacted their support, and they told me the app is wrong, and what Delta says is right. Okay. I also paid a bit of an upcharge on KLM to get an extra legroom seat. It's just a short hop, but the start of a VERY long journey, so I went for that route. Payment went through, I selected a seat. All seemed well.

Now cam the time to check in online (with KLM, as they operate the first leg). Weird thing number one is that I was not able (and still am not able) to check the seat map for the first leg and potentially move to a better seat. Initially, they blocked the first 6 rows for "business class" (which doesn't mean much on an E190 anyway), and I was right behind this. Hoping that the divider has been moved forward in the meantime, I wanted to check.. no "Can't do it, a payment is pending." What the heck? Well, shrug it off, go through the check-in, present all information needed, check-in successful. Trying to load the boarding passes in the KLM app, they didn't show up, telling me I need to go to the check-in desk at the airport. "Oh no, it's time for SSSS again", I thought, as this was the reason why I couldn't get my boarding pass online last time.

So I checked the KLM website. "Here's the PDF with your boarding passes, bro." No SSSS. Phew.
I checked the Delta website. "Here's the PDF with your boarding passes, bro." No SSSS either. Phew.
After waiting for the official check-in window to open on Delta (KLM gives you 30 instead of 24 hours), the Delta app also showed my boarding passes, no SSSS. For a strange reason, I can't save them to my Google wallet, but who cares. KLM App still refuses to load them.

Confusion doesn't end there. Remember the KLM app saying 1 bag, 23 kg/50 lbs, while Delta said two of them? The KLM website now says 3(!) bags, 32 kg/70 lbs each. Delta disagrees with that - at least their website and app agree on 2 pieces, 32 kg/70 lbs each. In practice, it doesn't make too much of a difference, as I usually do check 2 bags if I can (for redundancy in case one travels around the world without me), but the combined weight of them is less than 50 lbs.

My work for the most part is telling computers how to do things. Seriously, if we handed something like that to our customers, we would be out of business in no time. After working together for so much time, I would have expected that they got their stuff straight by now. But apparently, that is not the case.