I used PowerQueryBuilder to return records from a custom entity
#"Added Link" = Table.AddColumn(#"Changed Type", "Link", each Dyn365CEBaseURL & "/main.aspx?etn=new_Custom1&pagetype=entityrecord&id=%7b"& [new_Custom1id]&"%7d"),
#"Result" = if List.IsEmpty(ResultsList)
then ResultsTable
else #"Added Link"
in
#"Result"
I checked the data in the record GUID field., extracted the GUID from the URL, compared and there is not an issue.
In my Report I applied conditional formatting to the record name to provide a link from the Link column.

Here is the analysis I did on the data; note I have removed the actual link data.
PowerQuery_URL_Issue.xlsx