1.8 client doesn't show join message correctly

[RaphiMC]

How it should look: (1.19)

How it looks with 1.8:

The relevent config section:

joinMessage:
enable: true
text: '{"text": "&7---------- &c&lWord of warning &7----------
\n&61. &cThe IP of the server is public and shared, so it might be banned on some servers.
\n&62. &cUse the proxy at your own risk. You might get banned on some servers when doing so.
\n&63. &cOn some versions block bounding boxes and mining speeds cause bugs as they got changed. You may need to break blocks multiple times before they disappear.
\n&7-----------------------------------
\n&aWelcome to the &5ViaProxy &aconnector!
\n&aOfficial discord: &6https://discord.gg/dCzT9XHEWu
\n&aType &5/viaproxy &ato get started.
\n&aTo join online mode servers you need to install the following mod: &6https://github.com/RaphiMC/OpenAuthMod/releases/latest"}'