Connectivity between Switches

Have a Dlink 5 port switch with “extra” up-link port. Just bought a Netgear FS605, 5 port switch with “Auto-uplink”. Can’t get connectivity between two switches. Used the straight-thru cable that was originally hooking one PC on third floor, plugged between a port on Negear and EITHER the Up-link port or standard port on DLink switch, no good. Do I need this to be a crossover cable instead of thru? Tried revversing rolls. Both cases, 3rd floor see each other, 2nd floor sees, but not across entire lan

Thanx