Surname alphabetical order influences voting in elections with multiple votes?

For my borough council, it happened that we had 2 councillors to elect for the ward, this year. When I looked at the results, I found that for the four parties that each put up two candidates, all of them got between 5% and 24% more votes for their first named candidate, compared to their second - the results, and the ballot paper, were ordered alphabetically by candidate surname.

Could be coincidence (I can say the first-named Lib Dem is a long-standing councillor, so it wouldn't be that surprising if he got a few votes for him and not the other, if he's done a good job). But now I looked at Stevenage (where I grew up), and again there was one ward with a double election - St. Nicholas. And again, all 5 parties had their first-named candidate getting between 8% and 30% more votes than their second. And in this case it was a tight contest between Labour and Reform - and Reform's first candidate came above Labour's second, both alphabetically and in votes:

Matthew Hurst Reform UK 666 - Elected (2 year term)
Ian Marshall Reform UK 616
Claire Parris Labour and Co-operative Party 716 - Elected (4 year term)
Carolina Cristina Veres Labour and Co-operative Party 590

Again, it could be coincidence, but with 9 out of 9 cases favouring the first-named candidate, I think it's more like a pattern. I think there have been a significant number of people thinking they only have one vote (despite it being explained to them verbally and on the ballot paper), and giving it to the top-named candidate for their preferred party. And in the Stevenage case, that may have made the difference between 2 Labour candidates getting elected from the ward, and the (surprising, unless again there happens to be a marked local preference for a candidate) split decision that actually happened.

Anyone else know of wards electing multiple people (especially, as in these 2 cases, where most of the council was electing just one per ward, meaning the "you get 2 (or 3) votes" message may not have been so widely publicised?