Toilet keeps running!
If the refill hose is placed into the overflow tube (as opposed to clipped above it, as it should be), it could cause a siphon issue resulting in a continuous lowering of the tank water level.

This would normally cause the toilet fill valve to cycle on intermittently (to fill the tank when the level drops low enough to actuate the fill valve float mechanism), as opposed to continuously (you wrote "keeps running"). However, the "running" noise you are hearing might be the sound of the siphoning process itself. video explanation

This phenomenon is well known and can happen with most any fill valve (I won't say all because I just don't know). Your fill valve should have been equipped with a clip or tube guide to hold the refill hose above the overflow tube or to hold it just inside but not lower than the tank water level.