Assuming all components are OK and connected in configuration as per your drawing, you will always have some problems because of unfortunate use of 4 NPN BJTs ..
It is impossible to "saturate" both high-side NPNs driving them from the same supply voltage ..
TIP141 is a Darlington BJT and to "saturate" it you will need at least 2V Vbe, and in the same time you want the emitter voltage to go as high as possible, ideally as high as the supply voltage ..
One option to avoid this issue is to drive the high-side NPNs of higher voltage .. see similar scenario (with N-channel MOSFETs) on the attached picture ..
Alternatively use two PNPs as the high-side switches and re-configure the bridge ..
Regards,
IanP