We are facing exactly the same issue here with Google and the sitemaps. I have already contacted the Shopify Plus support team, but they only told me that "sitemap.xml" should be used from February 15 on exclusively. The four existing child sub-sitemaps should NOT be used as officially, these won't work any more since then. Well, they do as of now - I tested it...
However, neither the /sitemap_pages_1.xml works nor does the /sitemap.xml load the pages. The /sitemap.xml only loads the child sub-sitemaps /sitemap_products_1.xml, /sitemap_collections_1.xml and /sitemap_blogs_1.xml but not the pages. Exactly what happens to the thread opener AquaLiv.
My question is if anyone could solve that issue? I mean, it is really important for everyone I assume, and we do not have any access to the sitemap.xml. And it is Google, so it should work with the most important search engine, right?
I've brought this issue up with support and on the Partners Slack as well and have yet to receive any sensible response. Support told me that sub-sitemaps shouldn't be submitted, which I only did for testing purposes. Nobody at Shopify seems to really be aware of this issue or what the actual problem is, when it's pretty clear from looking at any Shopify store in Search Console. The pages sub-sitemap is simply being ignored while the other sub-sitemaps are being processed correctly.
I'v also been in contact with Shopify about this issues. I have communicated with them about it 3 times and was told last time that technical support would keep me posted on the issue. That was 2 weeks ago and, still I've heard nothing.
That last Guru that I spoke with was told to tell me to contact Google. That's a joke, how exactly do I do that? This probably is a Google issue not Shopify's but, as it is effecting Shopify stores it should be up to Shopify to work the issue out with Google, not an individual store owner.
Well, it may actually be a Shopify problem, and it wouldn't be a surprise.
When listing the sub-sitemaps, the header of the successfully submitted sitemaps reads as follows:
Whereas, the only sub-sitemap that manages to not be read by Google reads like this:
I know that this is for xml sitemaps defining images for the relevant links, but the extra code is also on the blog's sitemap without any images being defined there. I may be completely wrong, but it's just a thought.
I have looked at the sitemaps of 3 different Shopify stores, including our own and, all of them use the header "<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">". I can't say for sure, but I am assuming that all Shopify Stores' sitemaps will be set up the same. If it is a Shopify error than that could potentially mean every single Shopify sitemap is not being correctly read by GSC. If that was the case then I would hope Shopify is doing something to correct the problem and is making it a priority. On the other hand if it is a GSC issue, it could take month/years to see it fixed.
I first alerted Shopify to this issue on June 25/19 but have notice that GSC has not read it correctly since they migrated everything over to the new GSC in February. Our store has been up for several years and this is the same sitemap setup we've had for sometime and GSC never had any issue reading it until February of this year.
Though I have contact Shopify 3 times about the issues I still have not heard anything back from them re: solution.
In any case, it would be nice if Shopify would give us an update as to whether this issue is being addressed or not.
I just had a look at the individual child site maps and IAP is absolutely correct the pages sitemap is different than the rest. and is missing the xmlns:image="http://www.google.com/schemas/sitemap-image/1.1" so he could be on to something but it still doesn't explain why GSC could read it before but not now.