Identification: Convallaria

Can anyone identify what is happening to my Convallaria? Interestingly, nearby Solomon’s Seal is similarly afflicted. Thanks in advance. They are planted under lilacs and get filtered sun. Soil is decent.

 

I've seen this also, so it may be regionally prevalent but not seen everywhere (got nothing relevant on web). Have assumed it was pest damage like slugs in past, maybe go out and look at yours during the night.

 

I didn’t think of slugs, which I have in abundance, because there is no slime. But I will take your advice, thanks.