Japanese reader here. It got axed by the publisher because it's getting no-where. If you like stories about middle-aged guys getting sent to another world, read these mangas one instead:
1. The Wolf Won't Sleep
2. Yajin Tensei: Karate Survivor in Another World
Or if you're into guns in another...
I'm not sure if it was the author or the editor's decision, but basically, they opt-out not to use the original artist because he was quite expensive. No shit, no wonder why.