I have created a list made up of custom site columns, each of which is a Single Line of Text with a maximum of 255 characters.
After 24 hours the properties have still not appeared in the list of Crawled Properties available via /_layouts/15/listcrawledproperties.aspx?level=sitecol. They also do not appear in the list of Crawled Properties available via SharePoint Administration (Classic version) where the tenant-level settings are.
I have followed the advice of this post, and marked the list and site for reindexing, but that did not work either:
I have followed the advice of this blog post as well
I have found the columns in the list of ManagedProperties and CrawledProperties that are returned in XML when you call the search api and specify the ManagedProperties and CrawledProperties in the refiners query string parameter. I have also performed searched against these properties
I have viewed the crawl log and seen that the items featuring these custom columns have all been crawled.
I have also verified the settings on Site Settings > Searchable columns, and Site Settings > Search and offline availability
I have checked that the all of my services are healthy via the Service health section of the Microsoft 365 admin centre.
However, despite all of this, the properties still do not appear in the Search Schema UI, which would then allow me to map the properties to RefinableString managed properties so that I can use them for refining search as well as performing search operations.
I created the list on Thursday 20th of June 2019, and as of now the properties have not been created.
Could someone please contact me to look into this issue?