Eclipse -> not able to step through code using GDB...not sure why?

I am new to Eclipse. I am using a JLink Edu. I am following the Blinky-ARM tutorial. I am able to connect to the GDB server. e.g. of some output:

...Target halted (PC = 0x000002E0)
Reading 64 bytes @ address 0x00009840
Read 2 bytes @ address 0x00009854 (Data = 0x0802)
Received monitor command: regs
R0 = 00000001, R1 = 00000001, R2 = 20006F44, R3 = 2000115C
R4 = 200081D0, R5 = 00000001, R6 = 00000000, R7 = 20002B30
R8 = FDEF76DE, R9 = BFD5FF5F, R10= 695ECEF6, R11= BC7F777C
R12= 00000001, R13= 20002B58, MSP= 20002B58, PSP= 0E9E8FD8
R14(LR) = FFFFFFF9, R15(PC) = 000002E0
XPSR 01000000, APSR 00000000, EPSR 01000000, IPSR 00000000
CFBP 00000000, CONTROL 00, FAULTMASK 00, BASEPRI 00, PRIMASK 00
Reading all registers
Setting breakpoint @ address 0x00009854, Size = 2, BPHandle = 0x0005
Starting target CPU...

I have gone through (several times) setting up a debug config. I am debugging on -device ATSAMD21G18. My challenge is After starting the debug session, Eclipse is not going to the beginning of main(), e.g.:

main(void)
{
  printf("Hello ARM World!" "\n");
  return 0;
}

Can't step through (options greyed):
I thought perhaps I needed to copy the .hex file onto the SAMD21 (target) so I used Jlinkexe (I'm on a mac) and loadfile to copy the .hex. This didn't help. I think I must be missing something stupid? Any help appreciated. Thank you.