Redshift does not work properly if you use mobile broadband, etc. One way is to use redshift manually.
1. Install redshift via package management
2. Make config file and a laucher for redshift
mkdir -p $HOME/.config/redshift
In Mint 21 redshift.conf must place into $HOME/.config
… the contents (for Puolanka and Kajaani)
; Global settings for redshift
; Set the day and night screen temperatures
; Disable the smooth fade between temperatures when Redshift starts and stops.
; 0 will cause an immediate change between screen temperatures.
; 1 will gradually apply the new screen temperature over a couple of seconds.
; Solar elevation thresholds.
; By default, Redshift will use the current elevation of the sun to determine
; whether it is daytime, night or in transition (dawn/dusk). When the sun is
; above the degrees specified with elevation-high it is considered daytime and
; below elevation-low it is considered night.
; Custom dawn/dusk intervals.
; Instead of using the solar elevation, the time intervals of dawn and dusk
; can be specified manually. The times must be specified as HH:MM in 24-hour
; Set the screen brightness. Default is 1.0.
; It is also possible to use different settings for day and night
; since version 1.8.
; Set the screen gamma (for all colors, or each color channel
; This can also be set individually for day and night since
; version 1.10.
; Set the location-provider: 'geoclue2', 'manual'
; type 'redshift -l list' to see possible values.
; The location provider settings are in a different section.
; Set the adjustment-method: 'randr', 'vidmode'
; type 'redshift -m list' to see all possible values.
; 'randr' is the preferred method, 'vidmode' is an older API.
; but works in some cases when 'randr' does not.
; The adjustment method settings are in a different section.
; Configuration of the location-provider:
; type 'redshift -l PROVIDER:help' to see the settings.
; ex: 'redshift -l manual:help'
; Keep in mind that longitudes west of Greenwich (e.g. the Americas)
; are negative numbers.
; Configuration of the adjustment-method
; type 'redshift -m METHOD:help' to see the settings.
; ex: 'redshift -m randr:help'
; In this example, randr is configured to adjust only screen 0.
; Note that the numbering starts from 0, so this is actually the first screen.
; If this option is not specified, Redshift will try to adjust _all_ screens.
…. save and quit
…. a contents
redshift -l 64.283:27.683332
… save, quit and make it executable
chmod +x $HOME/.config/reshift/redshift
3. Add redshift script to the startup applications or make a launcher from
PS. You can find the right location from clock settings in Mate desktop, but replace commas using dot.
Read also: https://wiki.archlinux.org/title/redshift