Can't change any options

I try to use /set plugins.var.ruby.buffers. and weechat acknowledges that an option was changed, but nothing changes in the bar.
Even after reloading all the colors and the lagmeter stay the same.

[kabaka]

I'm entirely unable to recreate this issue so far.

Could you show me an example command that you're using?

For example, my buffers list shows:

After typing /set plugins.var.ruby.buffers.lag_bg 12 (without restarting or typing any further commands) I see:

Additionally, what version of WeeChat are you using?