Azure Table Storage REST API not returning data

I eventually achieved my goal by taking a different approach. Rather than generating a query string to pull the last 60 or 65 minutes of data and processing it to find the most current value, I created an Azure function app and table storage to store the most current value of the sensor reading.

The table, SensorDataExport, is set up so that the device's ID is the PartitionKey and the desired sensor reading is the RowKey. It has one additional property named sensorValue. The function app loads all the entities from SensorDataExport and loads the last 65 minutes of data from the devices historical logs table. It then finds the most current value and writes it back to the SensorDataExport table. I didn't try loading only 60 minutes of data, so maybe 65 minutes is a magic number. My function app runs every minute, but I think I could adjust that back to every 3 minutes. As a bonus, since PartitionKey and RowKey are indexed properties, the query string returns data in 1-2 seconds vs the 4-6 seconds it took before. All of this worked flawlessly for the 48 hour test I did.

Sample entity from the table:

PartitionKey  RowKey  Timestamp                     tagValue
1234567       LEVEL   2025-04-11T14:31:30.1186383Z  53.2

And the Azure Function App:

using Microsoft.Azure.Functions.Worker;
using Azure.Data.Tables;
using Azure;

namespace UpdateSensorDataExport
{
    public class UpdateSensorDataExport
    {
        [Function("UpdateSensorDataExport")]
        public async Task Run([TimerTrigger("0 * * * * *", RunOnStartup = true)] TimerInfo myTimer)
        {
            var serviceClient = new TableServiceClient(Environment.GetEnvironmentVariable("AzureWebJobsStorage"));
            var globalTable = serviceClient.GetTableClient("SensorDataExport");

            await foreach (var entity in globalTable.QueryAsync<TableEntity>())
            {
                string device = entity.PartitionKey;
                string sensorName = entity.RowKey;

                string historyTableName = $"{device}HistoryValues";

                var historyTable = serviceClient.GetTableClient(historyTableName);

                // Get latest history value using string 'date', limited to entities from last 65 minutes
                var cutoff = DateTimeOffset.UtcNow.AddMinutes(-65);
                var historyEntities = historyTable
                    .Query<TableEntity>(e => e.GetString("tagName") == sensorName && e.Timestamp >= cutoff)
                    .Where(e => e.ContainsKey("date"))
                    .ToList();
                var latestHistory = historyEntities
                    .OrderByDescending(e => DateTime.Parse(e.GetString("date")))
                    .FirstOrDefault();

                if (latestHistory != null)
                {
                    string newTagValue = GetSensorValueAsString(latestHistory);

                    // Update GlobalTagExport
                    entity["tagValue"] = newTagValue;
                    Console.WriteLine(newTagValue);
                    await globalTable.UpdateEntityAsync(entity, ETag.All, TableUpdateMode.Replace);
                }
            }
        }
        private static string GetSensorValueAsString(TableEntity entity)
        {
            var value = entity["tagValue"];
            return value?.ToString();
        }
    }
}