I've had many edit conflicts over the years but I have always been able to get my own wikitext one way or the other, for example by pressing "Show changes" or just directly in the textarea. Today, on https://sv.wikipedia.org/wiki/Wikipedia:Wikipediafr%C3%A5gor i edit conflicted with Larske and was not able to get my wikitext in any way. Not in the textarea and not when pressing "Show changes". When I did press "Show changes", it just said "(No difference)".
I am not using the edit conflict beta feature.