PnP Core Search API does not return all records with pagination enabled

Question

I'm attempting to retrieve a list of 300 sites under our tenant using the approach outlined below, as recommended in the official documentation:

var searchResults = new List<Dictionary<string, object>>();

var paging = true;
var startRow = 0;
const int ResultsPerPage = 50;

while (paging)
{
    var searchOptions = new SearchOptions("WebTemplate:GROUP")
    {
        StartRow = startRow,
        TrimDuplicates = false,
        RowsPerPage = ResultsPerPage,
        SelectProperties = new List<string>() { "Path", "Title" },
    };

    // Issue the search query
    var searchResult = await context.Web.SearchAsync(searchOptions);

    // Add the returned page of results to our search results list
    searchResults.AddRange(searchResult.Rows);

    // If we're not done yet update the start row and issue a query to retrieve the next page
    if (searchResults.Count < searchResult.TotalRows)
    {
        startRow = searchResults.Count;
    }
    else
    {
        // We're done!
        paging = false;
    }
}

// Process the total search result set
return searchResults.ToDictionary(x => $"{x["Path"]}", x => $"{x["Title"]}");

However, I'm facing an issue where I don't receive all 300 sites in the response. Instead, I'm only getting around 250 sites.

Strangely, when I increase the ResultsPerPage count from 50 to 300, I receive all 300 sites accurately. Additionally, I'm encountering duplicate entries when the ResultsPerPage count is set to 50.

I suspect there might be something I'm missing in how pagination works with the search API. Can anyone provide insights or guidance on this issue?