Justyna: With all due respect, this issue shouldn't be marked as "Invalid" for the reasons listed. This is not an issue with third party Marketplace content, this is an issue with the Mojang's Minecraft Marketplace software.
Specifically, the third-party content was never successfully fully downloaded, nor installed. This points to an issue with the Marketplace directly, not the content.
I have given one example for one piece of third party content that is experiencing this issue, I am certain there are other examples. Hopefully, the support team will reconsider and look into this further.
Also, tried checking for corrupted data on the application via the Switch OS and got the message that "No corrupted data was found".
Mojang Team, Please apply a fix for this, it's the same issue as fixed previously on 1.19.63. See here on reddit all the folks reporting that it is happening again: https://www.reddit.com/r/Minecraft/comments/119v07e/unable_to_connect_please_restart_your_client/