problem

Hi, new member here. I'm posting because I have a Chinese elm air layer with leaves that have suddenly started drying out. It was air layered in mid April and has been growing strongly since then. Today I noticed the new shoots and leaves had started to dry out. I took a peek at the cut site...

I purchased my first bonsai January 13th and it looked amazing [pic 1], lots of very green leaves with the cat's tongue texture [pic 2]. I am using Green Green fertilizer biweekly in a pretty loose soil [pic 3]. I water when the top soil is dry, every 1-2 days, I have an artificial light set up...

Yes I know it isn't a bonsai but I need some help. This the trunk of a lilac tree that is probably about 30 years old. The last couple of years it has seem to be declining. Fewer flowers, fewer leaves etc. I have read about lilacs shreddig their bark etc but the trunk appears weird to me. Can...