Please add unit tests to cover your use case and to be sure nothing else is broken

I'd like to suggest you another approach to fix that:

    if (this.options.lineHeight === 'auto') {

      ...

      if (lineHeightCss !== "normal") {
        lineHeight = Math.round(parseFloat(lineHeightCss));
      }

      this.options.lineHeight = lineHeight;
    }

    if (this.options.maxHeight === undefined) {
      this.options.maxHeight = Math.round(parseFloat(this.options.lines)) * Math.round(parseFloat(this.options.lineHeight));
    }

    ...

What do you think?
It has worked nicely for me!

Yes it's correct. But I'm not sure someone will one day say: I want 1.6 lines :) (this.options.lines).

So I think the best think to do is:
this.options.maxHeight = Math.round(parseFloat(this.options.lines)) * parseFloat(this.options.lineHeight));

@rogeriotaques Can you create a PR with a fix and with test? @drukepple did not answer. Or if you are patient I will do it myself. This fix will be in the version 1.2 anyway

Hey, @Tuizi!

Oh my Gosh! It has been quite a (very) long time since you proposed that solution and I totally forgot to give you a PR, really sorry. 🙇‍♂️

I checked the release page and I don't think the version 1.2 was rolled out, am I right?

Is this project still active?