I've seen someone else report this, but I was unable to reproduce. So something in your environment is perhaps triggering a bug in Thunderbird. What type of mouse/touchpad and other hardware?

Standard laptop Lenovo B-51 80, Windows 10 Home.

Mine is on an older HP ProBook 4540. Windows 10Pro 22H2, current updates, current logitech mouse drivers.

Crazy how bad this makes the UI - I've been using Thunderbird for 20 years and loving it - this is awfully painful.

This occurs for me when dragging a message to be dropped in a folder. Some of my local folders have a subfolder named "mbox" that was created when I imported old email. I certainly do not want to drop new messages into the "mbox" subfolder.

I think the auto-expand was occurring before, but in the new release it occurs much quicker.

Dell desktop, Windows 11 23H2

I think this same problem occurred on a previous update too. It was either fixed by a new release or I found a work-around - I can't remember the details now! Wouldn't it be nice if there was a user setting to adjust the delay for the auto-expanding of folders. My reaction time is not fast enough to beat the current setting.

Mine is on an older HP ProBook 4540. Windows 10Pro 22H2, current updates, current logitech mouse drivers. Crazy how bad this makes the UI - I've been using Thunderbird for 20 years and loving it - this is awfully painful.

The issue appears to be resolved!

Under the upgrade to "115.5.2 (32-bit)" and the functionality is back to the desired 'hover for a couple seconds' to open a subfolder, and no longer requires the lightening fast reflexes to drop a message into folder that has subfolders. It's delightful for Thunderbird to feel 'normal' again!

Just additionally updated to "115.6.0 (32-bit)" and the 'hover over folder' is still working as expected.

Thanks to whomever happened to put a fix in!!

jotb said

Mine is on an older HP ProBook 4540. Windows 10Pro 22H2, current updates, current logitech mouse drivers. Crazy how bad this makes the UI - I've been using Thunderbird for 20 years and loving it - this is awfully painful.

The issue appears to be resolved!

Under the upgrade to "115.5.2 (32-bit)" and the functionality is back to the desired 'hover for a couple seconds' to open a subfolder, and no longer requires the lightening fast reflexes to drop a message into folder that has subfolders. It's delightful for Thunderbird to feel 'normal' again!

Just additionally updated to "115.6.0 (32-bit)" and the 'hover over folder' is still working as expected.

Thanks to whomever happened to put a fix in!!

Yes, this is listed in the fixes for 115.5.2 https://www.thunderbird.net/en-US/thunderbird/115.5.2/releasenotes/