Formula error with linked column

I have what I think is a simple formula that is giving an incorrect sum. SUM({Actual Time#Hours}, {Sub-Item actual time}, {PO Time})
ActualTime#Hours = Time Tracking column
Sub-Item actual time is a linked column to a Time Tracking column
PO Time is a mirrored column = Time Tracking column
The result of the Formula is this: SUM(1h 18m 1s, 0, 30m 0s) = 1,801.3 hours

By may calculations it should equal 1.8003 hours. For some reason the formula is moving the decimal point. Have I done something wrong, and why is this only happening on pulse’s where the PO time has data in it?

It has also happened on a pulse where it only has sub-item time tracking for 4h 44m (4.7333 hours) and giving a total of 17,091 hours

Has anyone else run into this?

I figured out what was happening. Subtask-Actual time and PO Time we being treated as seconds!
My original formula was;
SUM({Actual Time#Hours}, {Sub-Item actual time}, {PO Time})
and by changing it to;
SUM({Actual Time#Hours}, {Sub-Item actual time}/3600, {PO Time}/3600)
The total time calculations are correct in hours