Considering your lager yeast is working in cool environment, fermentation in general and the first signs of activity will be somewhat delayed over what you may be used to in an ale with higher ferm temps.
Yeast, when stressed, tends to throw some flavors that can be a good thing or a bad thing. In the case of a clean lager, this is considered a bad thing. In the case of a Hefeweisen, stressed yeast throws esters and phenols, and this is a good thing to many brewers. So, yeast management can vary according to your beer and your goals.
So, what do you do now? First and foremost, temperature stability is key in a lager. Give this beer some time considering it is probably stressed trying to build a yeast count. Personally, I'd give your lager a few more days at 50F than you may have planned. Then, go up slightly toward 65F for your D-Rest where fermentation will be more active and finish up and hopefully clean itself of some unwanted flavors. Cold crashing in your fermenter and adding some gelatin finings is a technique I employee.
If I may suggest, take a look Brulosophy and read their take on lager beers. Lagers can be very rewarding but also very tricky. Temp control and proper yeast management will reward you with a clean lager.
Yeast, when stressed, tends to throw some flavors that can be a good thing or a bad thing. In the case of a clean lager, this is considered a bad thing. In the case of a Hefeweisen, stressed yeast throws esters and phenols, and this is a good thing to many brewers. So, yeast management can vary according to your beer and your goals.
So, what do you do now? First and foremost, temperature stability is key in a lager. Give this beer some time considering it is probably stressed trying to build a yeast count. Personally, I'd give your lager a few more days at 50F than you may have planned. Then, go up slightly toward 65F for your D-Rest where fermentation will be more active and finish up and hopefully clean itself of some unwanted flavors. Cold crashing in your fermenter and adding some gelatin finings is a technique I employee.
If I may suggest, take a look Brulosophy and read their take on lager beers. Lagers can be very rewarding but also very tricky. Temp control and proper yeast management will reward you with a clean lager.