iMac random restarts - timed-out on cpu 7, NMI-ing?

I'm experiencing random restarts and I'm really starting to pull my hair out. I tried to run Apple Diagnostics (holding D when booting up) which then prompts me to select my wifi which I do, it then just sits there. One time it ended up with the exclamation mark logo on top of the globe with support.apple.com/mac/startup -2002D underneath but that's as far as diagnostics got.

Hoping someone can give me some advice please.

edit: the example below has mp_kdp_enter() timed-out on cpu 7, NMI-ing but I've also received it for these (if it helps)

mp_kdp_enter() timed-out on cpu 1, NMI-ing

mp_kdp_enter() timed-out on cpu 0, NMI-ing

mp_kdp_enter() timed-out on cpu 4, NMI-ing

Machine-check capabilities: 0x0000000000000c0a
 family: 6 model: 158 stepping: 9 microcode: 248
 signature: 0x906e9
 Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz
 10 error-reporting banks
Processor 6: IA32_MCG_STATUS: 0x0000000000000005
 IA32_MC3_STATUS(0x40d): 0xfe40584000200135
 IA32_MC3_ADDR(0x40e):   0x0000000a4432c444
 IA32_MC3_MISC(0x40f):   0x0000000002122285
Processor 7: IA32_MCG_STATUS: 0x0000000000000005
 IA32_MC3_STATUS(0x40d): 0xfe40584000200135
 IA32_MC3_ADDR(0x40e):   0x0000000a4432c444
 IA32_MC3_MISC(0x40f):   0x0000000002122285
mp_kdp_enter() timed-out on cpu 7, NMI-ing
mp_kdp_enter() NMI pending on cpus: 0 1 2 3 4 5 6
mp_kdp_enter() timed-out during locked wait after NMI;expected 8 acks but received 1 after 12078294 loops in 2100000001 ticks
panic(cpu 7 caller 0xffffff8019bb5f37): Machine Check at 0x00007ff81c033ce2, registers:
CR0: 0x0000000080010033, CR2: 0x000000010f6a2000, CR3: 0x0000000a3b32102e, CR4: 0x00000000003626e0
RAX: 0x00007ff81c251a30, RBX: 0x0000000000000000, RCX: 0x000000000000001d, RDX: 0x0000000000000001
RSP: 0x00007ff7b0ae6448, RBP: 0x00007ff7b0ae6470, RSI: 0x0000000000000008, RDI: 0x00007fa8e810a921
R8:  0x0000000000000008, R9:  0x00007fa8e810a921, R10: 0x0000000000000600, R11: 0x00007ff85ec9c800
R12: 0x00007fa8e810a921, R13: 0x00007fa8e810a921, R14: 0x00007ff85ec9c800, R15: 0x0000000000000008
RFL: 0x0000000000000246, RIP: 0x00007ff81c033ce2, CS:  0x000000000000002b, SS:  0x0000000000000023
Error code: 0x0000000000000000
 @trap_native.c:168
Panicked task 0xffffff9f1c56d038: 5 threads: pid 112: DumpPanic
Backtrace (CPU 7), panicked thread: 0xffffff95826fc0c8, Frame : Return Address
0xffffffd138dcfb40 : 0xffffff8019a70c7d 
0xffffffd138dcfb90 : 0xffffff8019bc5294 
0xffffffd138dcfbd0 : 0xffffff8019bb4da7 
0xffffffd138dcfc20 : 0xffffff8019a11971 
0xffffffd138dcfc40 : 0xffffff8019a70f5d 
0xffffffd138dcfd30 : 0xffffff8019a70607 
0xffffffd138dcfd90 : 0xffffff801a1db8eb 
0xffffffd138dcfe80 : 0xffffff8019bb5f37 
0xffffffd138dcff90 : 0xffffff801a1e533c 
0xffffffd138dcffa0 : 0xffffff8019a11e4f 

Process name corresponding to current thread (0xffffff95826fc0c8): DumpPanic

Mac OS version:
22G720

Kernel version:
Darwin Kernel Version 22.6.0: Mon Apr 22 20:54:28 PDT 2024; root:xnu-8796.141.3.705.2~1/RELEASE_X86_64
Kernel UUID: FC979E73-CAD7-35BF-812E-E4B3C923BA96
roots installed: 0
KernelCache slide: 0x0000000019600000
KernelCache base:  0xffffff8019800000
Kernel slide:      0x00000000196dc000
Kernel text base:  0xffffff80198dc000
__HIB  text base: 0xffffff8019700000
System model name: iMac18,3 (Mac-BE088AF8C5EB4FA2)
System shutdown begun: NO
Panic diags file available: YES (0x0)
Hibernation exit count: 0

System uptime in nanoseconds: 24742329524
Last Sleep:           absolute           base_tsc          base_nano
  Uptime  : 0x00000005c2c1ff59
  Sleep   : 0x0000000000000000 0x0000000000000000 0x0000000000000000
  Wake    : 0x0000000000000000 0x00000029a891cf38 0x0000000000000000
Compressor Info: 0% of compressed pages limit (OK) and 0% of segments limit (OK) with 0 swapfiles and OK swap space
Zone info:
  Zone map: 0xffffff8a4cbb5000 - 0xffffffaa4cbb5000
  . PGZ   : 0xffffff8a4cbb5000 - 0xffffff8a51bb6000
  . VM    : 0xffffff8a51bb6000 - 0xffffff8f1dc82000
  . RO    : 0xffffff8f1dc82000 - 0xffffff90b721b000
  . GEN0  : 0xffffff90b721b000 - 0xffffff95832e7000
  . GEN1  : 0xffffff95832e7000 - 0xffffff9a4f3b4000
  . GEN2  : 0xffffff9a4f3b4000 - 0xffffff9f1b481000
  . GEN3  : 0xffffff9f1b481000 - 0xffffffa3e754e000
  . DATA  : 0xffffffa3e754e000 - 0xffffffaa4cbb5000
  Metadata: 0xffffff8071c25000 - 0xffffff8091c25000
  Bitmaps : 0xffffff8091c25000 - 0xffffff8099425000
  Extra   : 0 - 0