Media Encoder adding milliseconds to renders

Hi all,

Very confused at the moment with a render that I'm trying to create from After Effects.

I have a project in After Effects with a comp of 5 seconds flat and am rendering with Media Encoder.  When I render my mac says the file is 5 seconds but then I upload it to our system it says 5 seconds 5 milliseconds.  I have since downloaded MediaInfo and this states the files are 5 seconds 5 milliseconds.

Due to the system I'm uploading it too the file needs to be 5 seconds FLAT!

Can't anyone help me fix this or understand why Media Encoder is doing this?!

Thank you in advance!