There's a couple of things that I'd maybe change for efficiency, here, @gazzo1967 ... but I don't have the time to address those right now.
I do think one thing that you could change immediately would be to use the 'Subtract from time' action from the 'Date Time' connector.
There is a chance that your time is maybe not subtracting correctly ... just a chance, though.
I think you would also want your Filter to be 'less than' ... no? Plus, if you really want push that, you could wrap each time with trim() in the expression builder.
((( I'm penning a 'proper' answer for you, too )))