I think you might have to convert your totalseconds variable to Days and show that as a decimal (not intuitive for your viewers, but would show the values on Y axis). You could have an adjacent summary table with your original measure to show them the actual values, so they don't have to do the conversion in their heads.
If this works for you, please mark it as solution. Kudos are appreciated too. Please let me know if not.
The Y axis of the bar chart only supports Numeric type values, and the data type of returned measure "AllocatedTimeCal" value is Text type... So when you put that measure in the "Values" field of bar chart, the system automatically converts it to Count (AllocatedTimeCal) to make display as numeric type due to the limitation of numeric type values. As @mahoneypat suggested, you can update the formula of measure "AllocatedTimeCal", so that it eventually returns a decimal value based on hour or day. Then it can display on the Y axis of bar chart directly.
Currently Power BI does not yet support Duration type displayed on the Y axis. You can vote here and write down your comments to make it come true in the future.