that was the March 9-13 week.
This (week with 12th of month) is true (usually) for both the Household Survey (which produces the unemployment rate and labor force participation rates among scads of other measures) and the Establishment Survey (which produces the headline non-farm payroll number)
I don't know how that aligns with the Kaiser workers coming back from strike (I haven't been following that, is it this one that ended March 23?)
https://www.msn.com/en-us/money/general/after-multiple-strikes-kaiser-workers-ratify-new-contract-ending-labor-dispute/ar-AA1Zgj8b?ocid=BingNewsSerp
I respond since MahatmaKaneJeeves posted that I might know something about it, but I had to Google it (well damn it, it looks like fucking Microsoft changed my search engine back to Bing ... I had a hell of a time this time, doing a lot of research, to get the default search engine in Microsoft Edge browser be Google -- they give only one choice (I had to reinstall Edge a couple of days ago, and this is when I found out they were dicking me over), and it took a lot of research to figure out how to change that, when Bing is the only choice, but there's a way to add other search engines, but one has to fill in 3 items, including "URL with %s in place of query", which for Bing looks like: "{bing:baseURL}search?q=%s&{bing:cvid}{bing:msb}{google:assistedQueryStats}". I finally found Google's for that: "https://www.google.com/search?q=%s", and it worked for several searches but well, not now.
On your hypothesis about healthcare job growth - I've seen a lot about it being the main component of job growth lately, but i haven't seen an explanation. My guess is that the leading wave of boomers is getting to the point where health issues really begin to accelerate. The oldest boomers were born in 1946, meaning age 80, and a lot of boomers are in their 70's now. So that's my guess.