It sounds to me like you moved something/the environment on a frame that wasn't zero.
Generally, you want to make sure that you have everything in place before you start animating your character(s). But if you have to move something - anything - then you should probably check that your frame is on 0. This applies to all environments, and a lot of times, characters. When you're trying to animate/move a limb, make sure it's that limb you have selected. There's a few different ways to animate overall. Some use a large amount of frames (400+) in a loop (I believe. I've never done it this way myself.) and then draw the camera up and/or back down to the action, I can't speak too much on this one. Others do the shorter loops (181 frames), but only use the 'golden frames' to render out with (60 - 119. The idea is that 60 is your starting frame - the beginning of the act. 90 is the end of the act. 120 is the starting starting frame once again. Since both 60 and 120 are the starting frames, you can delete the 120th frame. You won't technically delete it, just render an image series from 60 to 119.).
Watch how the parameters change from one number to another and then back (her head being the selected bone here):
The idea is that you're creating a back and forth movement, such as a blowjob. What moves in a blowjob? The head, mouth, and perhaps neck/throat. In the above example's case, it's really only the mouth and head (though the head is the focus here.). As it goes down the shaft, her head slightly twists and goes to the side a bit, and then returns to the previous point as it goes up. In the example for the head, both Twist and Side-Side start at 0.00 and both change as she goes down (Twist: -2.00, Side-Side: 10.00. Sometimes you'll have numbers like 1.33 or -7.69, I find it easier to remember the numbers if I round up or down. So 1.33 would become 1.00 and -7.69 would become -8.00). If you were to follow the head parameters above. Frame 60 would have 0.00 for both Twist and Side-Side, and as she deepthroats - frame 90 - they become -2.00 for Twist and 10.00 for Side-Side. Then frame 120 should have them both back at 0.00. Animating the camera for scenes like this isn't entirely necessary, but it does give some of the scenes some level of life as it's a little more than just characters moving back and forth.
This is a little further along than you probably are, but you don't really need to render out an animation in 4K or anything like that. It's unnecessary. 1080p (turn "Max Time (secs" to 0) at 600 Samples (should be "Max Samples") with the Post-Denoiser Start Iteration (under Filtering) at about 560 or so should be fine.
You must be registered to see the links
has a nice video on it, though I would only use these settings for animations only. Denoising should only be used as needed for still renders. (Also, if you'd like, I could send you over that manual sex animation tutorial I referenced in the other post. Shoot me a DM.)