Looping gif slides play in wrong order on first loop

I'm trying to make a simple looping GIF using timeline slides in Photoshop. There's 5 slides, all elements are the same apart from the text which changes on each slide. Each are JPEGs placed on different layers, and there's only one layer visibe per slide - meaning that they flick through as the GIF plays. The problem that keeps happening is that on the first play through, the GIF skips the second slide, so plays 1,3,4,5 and then goes back to the first slide and plays correctly (1,2,3,4,5). It then continues to play correctly if you keep running it so it's only glitching on that first run through - and I have no idea why! Is this just a glitch that can't be fixed, has anyone else had this problem before? It's obviously not the end of the world as it does play in the right order eventually - more just annoying and would be good to know if it can be fixed! Any help appreciated. Thanks 🙂