less proton energy with oblique incidence

[mimboch]

Hello,
I observed high proton energy of approximately 30 MeV with normal incidence, and around 3.5 MeV at a 45 degree angle of incidence.
I'm attaching you some images showing the propagation of the laser pulse at a 45 degree angle at different times .
I will appreciate any suggestion and any answer .
Thank you.