Promise.reject() continues with then() instead of catch()

I am making myself a library which retries failed promise "chain-parts" - I collect methods to be called and queue next phase only after previous succeeded.

Conceptually rounded up - my problems are more fundamental. This is where I arrived with debugging:

this.runningPromise
    .then(function() { 
        return Promise.reject();
    })
//;
//this.runningPromise
    .then(this.promiseResolver.bind(this))
    .catch(this.promiseRejector.bind(this))
    ;

Works, promiseRejector kicks in. When I uncomment out the two lines, works not. promiseResolver gets called.

Can't find anywhere anything. Nodejs 6.10.3 with browserify on Windows, Chrome.

via user8119317