Thank you.  Yes, I had just created a conf file based on page 4 of this thread, with all the same settings [except pool, user and pass].
My USB hub is an Anker powered hub, but I will try an different one - power could be the problem

Yes, I am using this:

What am I doing wrong?

I compiled cgminer from github/kanoi and it runs, however, all it seems to do is plateau adjusts and lowers the target frequency by 5MHz each time.
Sample output:

cgminer version 4.12.0 - Started: [2021-12-29 19:48:50.879]
--------------------------------------------------------------------------------
 (5s):0.000 (1m):0.000 (5m):0.000 (15m):0.000 (avg):0.000h/s
 A:8  R:8192  HW:0  WU:0.0/m
 Connected to sha256.pool.xxxx.com diff 8 with stratum as user xxxxx
 Block: 6e7f308f...  Diff:92.4K  Started: [19:55:26.956]  Best share: 0
--------------------------------------------------------------------------------
 SB management [P]ool management ettings [D]isplay options [Q]uit
 0: GSF 10050211: BM1397:01  80.00MHz T:80  P:0   (160:80)  |  0.0% WU:  0% |  0
.000 /  0.000h/s WU:0.0/m-------------------------------------------------------
 [2021-12-29 19:58:53.824] 0: GSF 0 - set ticket to 0x00/1 work 1/1.0
 [2021-12-29 19:58:54.028] 0: GSF 0 - setting bauddiv : 00 61 (ftdi/2)
 [2021-12-29 19:58:54.157] 0: GSF 0 - set ticket to 0xe0/8 work 8/8.0
 [2021-12-29 19:59:04.471] Stratum from pool 0 requested work restart
 [2021-12-29 19:59:13.792] Stratum from pool 0 requested work restart
 [2021-12-29 19:59:31.410] 0: GSF 0 - plateau adjust: target frequency 85.00MHz
-> 80.00MHz
 [2021-12-29 19:59:32.686] 0: GSF 0 - CompacF Bitcoin Miner (10050211)
 [2021-12-29 19:59:33.657] Stratum from pool 0 requested work restart
 [2021-12-29 19:59:34.405] 0: GSF 0 - set ticket to 0x00/1 work 1/1.0
 [2021-12-29 19:59:34.609] 0: GSF 0 - setting bauddiv : 00 61 (ftdi/2)
 [2021-12-29 19:59:34.740] 0: GSF 0 - set ticket to 0xe0/8 work 8/8.0
 [2021-12-29 19:59:53.317] Stratum from pool 0 requested work restart

Any help, please?