I searched in the threads but couldn't locate a topic like mine.

I purchased the LEM kit from HK Parts. Stripped the pistol down and reassembled it using the LEM parts kit.

Here is where I have problems and I'm hoping to get some help. I'm sure I did something wrong, but I'm not certain what that is.

I followed this series of videos

The hammer will not cock reliably. If it does, it will only cock once and then (when gently released) it will not cock again and the hammer strut goes out of position.

Where did I mess up?

I'm going to try it again and post pictures in a bit.

The hammer strut keeps coming out of position.

https://www.hkpro.com/attachments/match-lem-hybrid-trigger-installation-hkpro-pdf.295794/

There may be some helpful information here.

It's been a few years since I did mine, but did you orient the LEM cocking piece inside the LEM hammer correctly? The cocking piece spring also oriented correctly?

It's explained about 15 seconds into this video....

Yup. Everything is aligned as it should be.

I am considering sending it to HK.

Send it to James @ Teufelshund Tactical. He is a certified Heckler & Koch armorer and will get it repaired and back to you quickly. He has a stellar reputation.