I've tried replicating this and it changes in how it freaks out, but something is going wrong.
Few imgur screenshots first: imgur.com/a/Y8wT9Sx
To repeat:
I went here: lichess.org/hLs37LDS/black#3
Then I quickly speed through the moves holding my right arrow key. It quickly adds up the material incorrectly. The longer I hold the right arrow the 'more' material I gain.
I will note that if I open a new tab and try what I've done, it does not break (looks normal).
It continues to repeat on that tab if I refresh and try again.
Few imgur screenshots first: imgur.com/a/Y8wT9Sx
To repeat:
I went here: lichess.org/hLs37LDS/black#3
Then I quickly speed through the moves holding my right arrow key. It quickly adds up the material incorrectly. The longer I hold the right arrow the 'more' material I gain.
I will note that if I open a new tab and try what I've done, it does not break (looks normal).
It continues to repeat on that tab if I refresh and try again.