Nothing in the error logs (nothing ever, really).
It's not reliably reproducible either, I haven't had a single issue all day today, for example, even though I've been quite busy on the forum.
And it's also much more common in Firefox on Windows than Chrome on Windows than Chrome on iPad, in that order.
Not a biggie, perhaps at some point I'll be able to figure out why and I'll make sure to share my findings.