In Linux KDE TB asks if it should be set as system default e-mail client at every launch, even though it it is already registered as such. This dialogue should only appear on launch until it is set as default, and then no more.
System:
Kernel: 5.5.8-1-MANJARO x86_64 bits: 64
Desktop: KDE Plasma 5.18.3 Distro: Manjaro Linux
TB version: 68.6.0-0.1