Created attachment 182335 [details]
Here are two screenshots of the problem as described.

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SUMMARY


STEPS TO REPRODUCE
1. Open the Brave browser and maximize window
2. Hover over the launcher and pinned apps in the application bar

OBSERVED RESULT
Hover text/tool tip text will not appear as the correct width. The launcher text can appear too wide, whereas the neighboring Dolphin app icon text can appear too narrow. Moving the mouse back and forth results in text that is the correct width and incorrect width.

EXPECTED RESULT
All hover text/tool tip text should appear the correct width

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: Fedora Linux 42
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.14.0
Qt Version: 6.9.1

ADDITIONAL INFORMATION

fastfetch output:
         .';:cccccccccccc:;,.             -----------
      .;cccccccccccccccccccccc;.          OS: Fedora Linux 42 (KDE Plasma Desktop Edition) x86_64
    .:cccccccccccccccccccccccccc:.        Host: ASUS TUF Gaming A15 FA506NCR_FA506NCR (1.0)
  .;ccccccccccccc;.:dddl:.;ccccccc;.      Kernel: Linux 6.14.11-300.fc42.x86_64
 .:ccccccccccccc;OWMKOOXMWd;ccccccc:.     Uptime: 23 mins
.:ccccccccccccc;KMMc;cc;xMMc;ccccccc:.    Packages: 2436 (rpm), 29 (flatpak)
,cccccccccccccc;MMM.;cc;;WW:;cccccccc,    Shell: bash 5.2.37
:cccccccccccccc;MMM.;cccccccccccccccc:    Display (CMN1521): 1920x1080 @ 144 Hz (as 1749x983) in 16" [Built-in]
:ccccccc;oxOOOo;MMM000k.;cccccccccccc:    DE: KDE Plasma 6.3.5
cccccc;0MMKxdd:;MMMkddc.;cccccccccccc;    WM: KWin (Wayland)
ccccc;XMO';cccc;MMM.;cccccccccccccccc'    WM Theme: Breeze
ccccc;MMo;ccccc;MMW.;ccccccccccccccc;     Theme: Breeze (Dark) [Qt], Breeze [GTK3]
ccccc;0MNc.ccc.xMMd;ccccccccccccccc;      Icons: breeze-dark [Qt], breeze-dark [GTK3/4]
cccccc;dNMWXXXWM0:;cccccccccccccc:,       Font: Ubuntu (10pt) [Qt], Ubuntu (10pt) [GTK3/4]
cccccccc;.:odl:.;cccccccccccccc:,.        Cursor: breeze (24px)
ccccccccccccccccccccccccccccc:'.          Terminal: konsole 25.4.2
:ccccccccccccccccccccccc:;,..             CPU: AMD Ryzen 7 7435HS (16) @ 3.10 GHz
 ':cccccccccccccccc::;,.                  GPU: NVIDIA GeForce RTX 3050 Mobile [Discrete]
                                          Memory: 4.56 GiB / 15.43 GiB (30%)
                                          Swap: 0 B / 8.00 GiB (0%)
                                          Disk (/): 60.30 GiB / 450.73 GiB (13%) - btrfs
                                          Local IP (wlp3s0): 10.198.25.79/24
                                          Battery (A32-K55): 72% (1 hour, 45 mins remaining) [Discharging]
                                          Locale: en_US.UTF-8