GETH v1.10.16-stable (windows-amd64) refusing to CPU mine ropsten Eth

I have had a config working for more than a year. The past few weeks, I am suddenly seeing CPU hash rate of "0" (and no Eth received) despite the CPU load indicating mining. Historically I would be able to mine 5 - 20 test Eth per day.

• I have cleared the blockchain & re-downloaded the entire ropsten blockchain;
• I have cleared and re-generated the DAG;
• I have cleared and re-generated the cache.

I am starting with:

"c:\Program Files\Geth\geth.exe" --ropsten --http --http.api eth,net,web3,personal,miner,admin,txpool,debug --http.corsdomain '*' --http.addr 127.0.0.1 --http.port 8545 --metrics --mine --syncmode "full" --miner.etherbase 0x626B046B0Ce356F248b215b01B459F8B8d59E1A4 --datadir d:\Ethereum\ropsten\ --ethash.cachedir d:\Ethereum\ropsten\cache\ --ethash.dagdir d:\Ethereum\ropsten\dag\ --allow-insecure-unlock --maxpeers 9999 --maxpendpeers 9999 --whitelist 10920274=0xfd652086d220d506ae5b7cb80fde97d2f3f7028d346cc7d9d384a83d3d638532 --rpc.allow-unprotected-txs --txpool.globalslots=250000 --txpool.globalqueue=50000 --cache=1024

On the client:

Are we connected? Yes

C:\>"\Program Files\Geth\geth.exe" --exec "net" attach http://127.0.0.1:8545

{

listening: true,

peerCount: 1,

version: "3",

getListening: function(callback),

getPeerCount: function(callback),

getVersion: function(callback)

}

Are we synced up to date? Yes

C:\>"\Program Files\Geth\geth.exe" --exec "eth.syncing" attach http://127.0.0.1:8545

false

Lets start CPU mining:

C:\>"\Program Files\Geth\geth.exe" --exec "miner.start()" attach http://127.0.0.1:8545

null

Do we see this on the server? Yes

INFO [03-29|11:19:29.425] Updated mining threads threads=8

Lets check our hashing rate?

C:\>"\Program Files\Geth\geth.exe" --exec "eth.hashrate" attach http://127.0.0.1:8545

0

Server output looks like this:

INFO [03-29|12:08:00.665] Unindexed transactions blocks=1 txs=11 tail=9,795,819 elapsed="505.8µs"

INFO [03-29|12:08:00.678] Commit new sealing work number=12,145,819 sealhash=3865df..8989bb uncles=0 txs=0 gas=0 fees=0 elapsed=12.714ms

INFO [03-29|12:08:01.326] Commit new sealing work number=12,145,819 sealhash=a47838..9a58f7 uncles=0 txs=49 gas=7,985,638 fees=0.1164976668 elapsed=661.096ms

INFO [03-29|12:08:01.418] Imported new chain segment blocks=1 txs=52 mgas=7.991 elapsed=124.149ms mgasps=64.370 number=12,145,819 hash=b1a76d..3f7ab0 dirty=21.93MiB

INFO [03-29|12:08:01.487] Unindexed transactions blocks=1 txs=2 tail=9,795,820 elapsed=0s

INFO [03-29|12:08:01.487] Commit new sealing work number=12,145,820 sealhash=fc3c8c..19074a uncles=0 txs=0 gas=0 fees=0 elapsed=1.998ms

INFO [03-29|12:08:01.628] Commit new sealing work number=12,145,820 sealhash=732bf8..63547d uncles=0 txs=7 gas=7,998,893 fees=0.1292982716 elapsed=142.513ms

INFO [03-29|12:08:04.051] Downloader queue stats receiptTasks=0 blockTasks=0 itemSize=4.55KiB throttle=8192

INFO [03-29|12:08:04.755] Commit new sealing work number=12,145,820 sealhash=56d7e0..efade1 uncles=0 txs=7 gas=7,998,893 fees=0.1293770226 elapsed=251.877ms

INFO [03-29|12:08:04.834] Chain reorg detected number=12,145,803 hash=2b4997..77da38 drop=16 dropfrom=b1a76d..3f7ab0 add=16 addfrom=8dd997..e56423

INFO [03-29|12:08:04.852] Imported new chain segment blocks=16 txs=79 mgas=14.953 elapsed=742.791ms mgasps=20.131 number=12,145,819 hash=8dd997..e56423 age=2m11s dirty=22.09MiB

INFO [03-29|12:08:04.863] Commit new sealing work number=12,145,820 sealhash=5a0eed..8edf1c uncles=0 txs=0 gas=0 fees=0 elapsed=0s

INFO [03-29|12:08:04.991] Commit new sealing work number=12,145,820 sealhash=ec2088..a9d216 uncles=0 txs=35 gas=7,991,374 fees=0.401233045 elapsed=128.057ms

INFO [03-29|12:08:07.896] Commit new sealing work number=12,145,820 sealhash=99cfce..2922f6 uncles=0 txs=35 gas=7,991,374 fees=0.401233045 elapsed=27.511ms

Any ideas??

Its an Intel(R) Core(TM) i7-9700 CPU @ 3.00GHz (8 cores), 32 GB Ram, Windows 11 Home (64 bit).

https://www.intel.co.uk/content/www/uk/en/products/sku/191792/intel-core-i79700-processor-12m-cache-up-to-4-70-ghz/specifications.html

Have experimented with 8 threads, 6 threads, 4 threads etc

I use command: "\Program Files\Geth\geth.exe" --exec "miner.start(4)" attach http://127.0.0.1:8545

Frustrating, as this setup was working only a few weeks back!!