Incorrect thumb disassembly/detection

Hello,

I am working on some code for a cortex-M33 and see that the gdb
disassembly does not match that of objdump, but only when a target is
connected.

$ arm-none-eabi-objdump -d bin/usb_cdc.elf | awk -v RS=
'/^[[:xdigit:]]+ <main>/'
00000cb8 <main>:
     cb8:	b500      	push	{lr}
     cba:	b085      	sub	sp, #20
     cbc:	ab03      	add	r3, sp, #12
[-snip-]

$ gdb-multiarch bin/usb_cdc.elf 
GNU gdb (Debian 8.2.1-2+b3) 8.2.1
[-snip-]
(gdb) disas main
Dump of assembler code for function main:
   0x00000cb8 <+0>:	push	{lr}
   0x00000cba <+2>:	sub	sp, #20
   0x00000cbc <+4>:	add	r3, sp, #12
[-snip-]
End of assembler dump.
(gdb) target remote localhost:2331
Remote debugging using localhost:2331
0x00000000 in __isr_vector ()
(gdb) disas main
Dump of assembler code for function main:
   0x00000cb8 <+0>:	bl	0xd6e4 <USB__IsHighSpeedCapable+12>
   0x00000cbc <+4>:	cbz	r0, 0xcc8 <main+16>
   0x00000cbe <+6>:	ldrb.w	r1, [sp, #6]
[-snip-]
End of assembler dump.

stepping instructions increments the program counter by 2 indicating
thumb mode. So i expect the disassembly also to be thumb.

What is causeing the disasembly to change to arm mode when a target is
used?

Best Regards!