It just happened again so thought of sharing the error log report. Please see below. Thanks in advance... much appreciated.
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Sleep Wake failure in EFI
Failure code:: 0xffffffff 0x0000001f
Please IGNORE the below stackshot
================================================================
Date/Time: 2020-12-12 10:54:35 -0500
OS Version: ??? ??? (Build ???)
Architecture: x86_64
Report Version: 29
Data Source: Stackshots
Shared Cache: 0x508c000 0FE34038-0DB8-3353-B293-6897693E83AE
Event: Sleep Wake Failure
Duration: 0.00s
Steps: 1
Time Awake Since Boot: 84s
Process: swd [318]
Architecture: x86_64
Footprint: 372 KB
Start time: 2020-12-12 10:54:35 -0500
End time: 2020-12-12 10:54:35 -0500
Num samples: 1 (1)
Thread 0x910 1 sample (1) priority 4 (base 4)
<thread QoS background (requested background), thread darwinbg, process darwinbg, IO tier 2>
1 start + 1 (libdyld.dylib + 109769) [0x7fff6c375cc9] 1
1 ??? [0x108602454] 1
1 ??? [0x1086021dd] 1
1 __stack_snapshot_with_config + 10 (libsystem_kernel.dylib + 135862) [0x7fff6c4d72b6] 1
*1 ??? [0xffffff80002bf206] 1
*1 ??? [0xffffff8000982437] 1
*1 ??? [0xffffff800089afc1] 1
*1 ??? [0xffffff80002e29e7] (running) 1
Binary Images:
0x7fff6c35b000 - 0x7fff6c391fff libdyld.dylib (750.6) <789A18C2-8AC7-3C88-813D-CD674376585D> /usr/lib/system/libdyld.dylib
0x7fff6c4b6000 - 0x7fff6c4e2fff libsystem_kernel.dylib (6153.141.2.2) <5CDBBC06-6CA6-3432-9FDA-681047866F3E> /usr/lib/system/libsystem_kernel.dylib
Model: MacBookPro9,2, BootROM 233.0.0.0.0, 2 processors, Dual-Core Intel Core i5, 2.5 GHz, 10 GB, SMC 2.2f44
Graphics: kHW_IntelHD4000Item, Intel HD Graphics 4000, spdisplays_builtin
Memory Module: BANK 0/DIMM0, 8 GB, DDR3, 1600 MHz, 0x0000, 0x393930353432382D3135352E4130304C4620
Memory Module: BANK 1/DIMM0, 2 GB, DDR3, 1600 MHz, 0x80AD, 0x484D54343235533641465236412D50422020
AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0xF5), Broadcom BCM43xx 1.0 (7.21.190.33 AirPortDriverBrcm4360-1601.1)
Bluetooth: Version 7.0.6f7, 3 services, 27 devices, 1 incoming serial ports
Network Service: Wi-Fi, AirPort, en1
Serial ATA Device: APPLE HDD HTS545050A7E362, 500.11 GB
Serial ATA Device: HL-DT-ST DVDRW GS41N
USB Device: USB 2.0 Bus
USB Device: Hub
USB Device: Hub
USB Device: Apple Internal Keyboard / Trackpad
USB Device: IR Receiver
USB Device: BRCM20702 Hub
USB Device: Bluetooth USB Host Controller
USB Device: USB 2.0 Bus
USB Device: Hub
USB Device: FaceTime HD Camera (Built-in)
USB Device: USB 3.0 Bus
Thunderbolt Bus: MacBook Pro, Apple Inc., 25.1