ATTINY85 and NRF24L01+ only works with longer vcc/gnd lines on PCB
Just a guess: 

What your're doing when adding the extra VCC/GND wire for the nRF24 is to insert some inductance &amp; resistance. I assume that this decouples the nRF24 power supply from the ATTiny power supply. 

Radios like the nRF24 tend to draw a lot of current in a very short time, i.e. when the radio is activated. 

From your schematic and layout, I can only see very little capacitance (also the 10uF is not that much and because its an ALU type cap, it has high ESR.

I think you need to provide much more (low ESR) capacitance to your circuit, because the high current peaks of the nRF24 might disrupt your power supply.