NOTE: This is also the same for any Prime Gaming Bundle loot - if you claim any currency on Prime Gaming, it will only show on the platform you first claimed it on, so if you see a difference in your currency, and you've claimed Prime Gaming bundles recently this will be why.
Show-Bucks purchased on Switch is only available on that platform. All other platforms share currency. This means your balance may change depending on what platform you’re on. Examples are below:
eg.100 Show-Bucks purchased on EGS.
EGS/Xbox/Steam/PS will display 100 Show-Bucks available.
Switch will display 0 Show-Bucks available.
The restrictions outlined above apply to currency only. Any content purchased with your Kudos, like Costumes, will be available across platforms.