Logback appender not working

I am unable to get Sentry to send events using the logback appender.
I’ve copied the code from the example repo verbatim and yet there are no new events.

However, if I use the Sentry object (e.g. Sentry.capture(“foo”)) to manually send messages, it does work. This means that my DSN is set up correctly (I’m using a sentry.properties file in the root of my project).

My logback.xml can be seen here: https://hastebin.com/akibumutor.xml
Main class: https://hastebin.com/ezomobelag.java
Log output

07:19:51.767 [main] INFO gg.tradecentral.discord.core.Bot - Initializing Bot
07:19:51.832 [main] DEBUG io.sentry.DefaultSentryClientFactory - Using an HTTPS connection to Sentry.
07:19:51.879 [main] DEBUG io.sentry.DefaultSentryClientFactory - The current environment doesn't provide access to servlets, or provides an unsupported version.
07:19:51.880 [main] DEBUG io.sentry.SentryClient - Adding 'io.sentry.event.helper.ContextBuilderHelper@555590' to the list of builder helpers.
07:19:51.882 [main] DEBUG io.sentry.SentryClientFactory - Configuring uncaught exception handler.
07:19:51.883 [main] DEBUG gg.tradecentral.discord.core.Bot - Debug message
07:19:51.883 [main] INFO gg.tradecentral.discord.core.Bot - Info message
07:19:51.883 [main] WARN gg.tradecentral.discord.core.Bot - Warn message
07:19:51.885 [main] ERROR gg.tradecentral.discord.core.Bot - Caught exception!
java.lang.ArithmeticException: / by zero
    at gg.tradecentral.discord.core.Bot.sentry(Bot.java:75)
    at gg.tradecentral.discord.core.Bot.main(Bot.java:30)

I’ve been stuck on this for hours. What am I missing?