since 11-11-25+- I have been getting read & write errors when verifying downloads trying to update any game. Disk write failure, state 0x606

I have done chkdsk X: /f /r /x, clear cash, repair library, run as admin, re-install and many other recommendations, I even tried using another Hard Drive on a different controller. So its not the drive or the controller.

With the help of AI I found corrupted files in the downloads folder that where very hard to remove-

I checked AV, Hitman / Intercept X logs and there is nothing in any logs of steam related issues but I found other errors like:
2025-11-16T00:16:48.058Z SEDS Etw Warning SDR Trace SgEnableObjectReferenceSystemTrace failed
2025-11-16T00:16:48.058Z SEDS Etw Warning SG_PERF_OB_OBJECT trace failed to set to 0, 0x00000005
2025-11-16T00:16:48.058Z SEDS Etw Warning SDR Trace2 SgEnableObjectReferenceSystemTrace failed
What this actually means

SEDS = Sophos Endpoint Defense Service

Etw Warning = ETW = Event Tracing for Windows (Windows’ tracing system)

SgEnableObjectReferenceSystemTrace failed = Sophos tried to enable a specific ETW trace provider (for object/activity monitoring) and couldn’t

0x00000005 = Windows error code ERROR_ACCESS_DENIED

So in plain language:

"Sophos Endpoint Defense tried to enable a performance/trace source (SG_PERF_OB_OBJECT via SgEnableObjectReferenceSystemTrace) but Windows said access denied."

This is Sophos failing to turn on some of its own monitoring, not Sophos blocking Steam writes.

It’s about Sophos → ETW, not Steam → disk.
It’s a warning about tracing, not about blocking I/O.
Annoying, but not the smoking gun for your 0x606 error.

But I see other related/unrelated errors like: in sophos sls log: WinHttpSendRequest failed: 12007

Synchronous url reputation lookup ... longer than soft timeout
→ Sophos trying to ask the cloud “is this URL/file bad?” and the reply is slow or fails.

WinHttpSendRequest failed: 12007
→ 12007 = “name not resolved” (DNS / connectivity issue).

DeviceControl: Network connectivity changed
→ it noticed your network flapping / switching.

Enable: Started Safestore process / Clean process
→ starting the quarantine/clean helper processes, exiting normally with code 0.

Failed to create async event from request: message exceeds size limit ... DeviceIoControl_summary
→ Sophos tried to send a huge telemetry blob summarizing DeviceIoControl activity and the message was too big, so it dropped that event.

Important bit: There is nothing here about: steam.exe

So I don't think its the Antivirus.

I am on windows 10 with Extended Updates.
This started on or around MS patch Tue.
I think its the microsoft updates

Today I tried again and now and there are new issues:
download completes but during verification it says "Stopping Download".
I don't even get to the disk errors.
I wonder how Steam/valve is verifying downloads-am I dealing with a http, encryption/certificate error's??

I am at wits' end!
Please help!