74ls245 won't drive the data bus from 74hct377 8-bit Flip Flop
Fix your power distribution!  Use individual power and ground wires from the power supply to EACH breadboard - do not daisy-chain the power distribution through multiple breadboards.

The 74LS family is specified for operation between 4.75 and 5.25 volts - you can't expect proper operation at 3.5 volts.  The CMOS versions (74HC, but not 74HCT) are specified for operation from 2 - 6 volts. 74HCT is spec'd for 4.5 - 5.5 volts.