Time Machine drive not recognized after Tahoe update

JohnFIRL wrote:

I've done all the things suggested on other threads around similar issue. Set the 'allow accessories..' to 'always' to see if that helped. nope. Also disk utility doesnt see it (mind u takes forever to show the main mac hd drive also!). Using Apple adaptor for old usb to usbc. Restarted etc.. nothing. I use bit defender but it doesnt appear to have any settings for showing/not showing external hds. And this all worked before I updated !!

Problem reports related to antivirus software

• BitDefender may generate excessive read activity on the destination volume during a backup task, and may cause the destination device to spontaneously eject. Add the destination volume to BitDefender's exclusion list to avoid the problem.
• We have received and confirmed a report in which Sophos CryptoGuard can have a debilitating effect on system performance while running a backup task.
• We have received several reports that McAfee's FileCore and Symantec's Data Loss Prevention software can cause the backup task to hang or to take a very, very long time. The applicable daemon processes may also consume an exceptional amount of CPU during a backup task leading to debilitating system performance for the duration of the task.
• We have received a report that ESET Endpoint Security can cause the backup task to hang or to take a very, very long time.

Does the drive have its own power supply, or is it powered through USB? If bus-powered, it could be trying to pull too much current and shutting down the bus.

If you open Disk Utility with the external drive disconnected, does it show the internal drive immediately?

Disk Utility will hang up like that if the drive is failing or otherwise corrupt.

Let us guess.

" This is all Apples macOS 26 Tahoe Fault "

This will include BitDefender

Third Party AV Software could not possibly be the core issue

Windows-like viruses that self-replicate and affect macOS don’t exist because of the underlying UNIX Foundation and permission limitations.

The macOS operating system resides in a sealed and read-only volume that can’t be opened by users or third-party applications like BitDefender

Mac app security enhancements are sufficient to protect computers from malware.

Adware and Malware can affect computers and are often downloaded from “shady” websites or developers who inject them into downloads.

Source: User tip from @Kurt Lang

https://discussions.apple.com/docs/DOC-250008855

Picking up on the previous posting re - too much current

System Information >> USB

1 USB-C, USB Powered, SSD drive Directly connected using 304 mA