My theory (and it’s probably total bullshit/ but as someone who has owned professional service businesses my whole life I understand the mindset ) is that humans working service businesses hold off on raising prices as long as humanly possible because the idea of doing less units is terrifying (and raising prices leads to less units), but with consumer being maxed out (service providers are consumers for everything that does not involve them selling their services) and inflation running very hot the last 2.5 or 3 years the upward price pressure is very real.
Then, this happens in January, after a lot of people see a P&L for their business, along with January being a logical time to roll out changes (new years resolution- rethinking life- rethinking business- rethinking prices) and you have this pop that’s isolated to one month and goes back down to expected or lower next month especially with cost of goods dropping.
Like I said, this is just a WAG and I could be completely wrong but it makes some sense to me. I can’t imagine services driving inflation for a meaningful way for a long time. It’s too competitive a market and someone will always be willing to undercut someone else and take market share.