My best 2 800s were in relays and were 1:56.5 and 1:56.8.
1:56.5: 54.7, 61.8
1:56.84: 55.85, 60.99
However, since they were in relays they were produced by chasing people down. On the 1:56.5 I went nuts the first lap and caught 2 guys going through with a split of 54.7. I caught two more guys on the second lap and had no one else to catch and ran 61.8. The next guy was way ahead and unless I ran like a 1:52/1:53 split I wouldn't have caught him. Again on the second one I caught up to the one guy I was behind. On both of these however, I think I went out too fast ideally and would rather have had less than a 4 second positive split at minimum haha.
I have serious wheels though so I can get away with doing this sometimes. I wouldn't be surprised if I was able to run 49.X in a 4x4 split this year. When I did speed workouts this past track season I would handily beat our 51 second 400m runner. One time I went out in 25 seconds for the first 200 of an 800 and I even had the lead when I got the baton (ended up running 2:03 and winning the relay).
I think part of the issue that I have is that I win most of the 800s I run. I've done a 59,61 split before and won an 800 after a 4:23 1600. I've also done a 59,60+ 800 after a 1600 as well.
This season I'm going to try for something like 55+, 58-59. I know that once I get the strength to run under 60 seconds for my second lap I'll make the team for sure. I've never run my second lap of an 800 under 60 seconds.
As for your workout that's really strange. I wonder if not doing strides messed you up. You were doing each one faster and cutting them down which could have meant that you were slowly warming up.