[Post-Install] Mouse Cursor Stubs Its Toe When Moving Between Multiple Display Monitors Plus Emacs Behavior

[TheSupremeVizier]

I have just "allegedly finished" installing Kubuntu 25.04. It hasn't been easy. I learned some things like "update everything before you change monitor resolution or else start over".
I will cut to the chase. This is likely a two-part problem.

Part 1:
I run two display monitors side-by-side on one desktop. In 24.04, moving the mouse cursor from one monitor to the other was seamless and smooth. In 25.04, moving the mouse cursor from one monitor to the other results in a brief but very annoying hangup at the adjacent edge of the monitors when moving the mouse cursor at a sane speed. Transit is smooth if the mouse cursor is moved faster than a speeding bullet. I am running the same proprietary Nvidia driver in 25.04 as I was running in 24.04.

Is there some way to stop this very annoying hang-up "feature" and regain the previously enjoyed smoothness?

Part 2:
I am running

emacs -fg yellow -bg black -cr red -geometry 80x48 $@ &

inside a shellscript. I cannot effectively change the size of the resulting window by placing my mouse cursor on the lower or upper border or lower or upper corners since the resulting motion is limited to a "smidgen"...a highly technical term. I can only change the size of the resulting window by placing my mouse cursor on the side edges and making the window larger or smaller in the horizontal direction. This was not an issue with 24.04.

One more wrinkle for emacs which makes this a possible two part problem is that when I try to move the emacs window/xterm from one monitor to the other at a sane rate, if it is momentarily hungup during the crossing and then the emacs window/xterm immediately shrinks to about half of the original size, and it cannot be conveniently resized in the vertical direction. If I move the emacs window at an insane speed through this apparent barrier, there is no problem with "shrinkage"...no cold water involved in these experiments. ;-)

I do not have this problem with Konsole. How do I debug/fix this issue?

Thank you very much in advance.

[oshunluvr]

Part 1: This is a new feature. To disable it: System Settings > Mouse & Touchpad > Edge barrier: Change setting to "None"

I haven't used EMACS in decades. My guess is the issue lies with EMACS. This is literally the only comment I found about this on the WWW: https://www.reddit.com/r/kde/comment...is_very_laggy/

[TheSupremeVizier]

oshunluvr, thank you. I have removed the edge barrier and it works like a charm.
As for the age of emacs, that gives you additional insight into my age. I use multiple editors, but I really like emacs for certain editing tasks. Your mileage may vary. ;-)
I did not have this problem with emacs in 24.04 and I am using emacs-pgtk.

[jlittle]

(BTW, strictly IMO, if you've got two issues, it's better to make two posts.)

Part 1 sounds like a desktop effect. System settings, Window Management, Desktop Effects. But I couldn't find one that did that.

Part 2, which emacs is that? I installed the default, which is emacs-gtk, and after starting it from a script had no trouble "grabbing" the window "frame" on any side. Perhaps you've turned off the frame?

[TheSupremeVizier]

Hi, jlittle

$ apt --installed list | grep emacs

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

emacs-bin-common/plucky,now 1:30.1+1-5ubuntu1 amd64 [installed,automatic]
emacs-common/plucky,plucky,now 1:30.1+1-5ubuntu1 all [installed,automatic]
emacs-el/plucky,plucky,now 1:30.1+1-5ubuntu1 all [installed,automatic]
emacs-gtk/plucky,now 1:30.1+1-5ubuntu1 amd64 [installed,automatic]
emacs/plucky,plucky,now 1:30.1+1-5ubuntu1 all [installed]
emacsen-common/plucky,plucky,now 3.0.7 all [installed,automatic]

Let me know if I downloaded too much, and if so, how to trim it back and what I should trim it to. Thanks in advance.

However, I have news for you. I had the problem with emacs when I was running the default...Wayland.
The problem does not exist when I instead run X11.

Let me know if you consider this a bug worthy of notifying the authors.