Z wave in general and Aeon lbas gen 5

Hi everyone I’m not getting this really straightend out. I have some locations where my nodes dies on occation they could work for several days but every now and then I get error meassegs for an example node 8 i currently marked as dead by the controller. Then I Use IMA tools and try to heal network and node 5 6 7 has 8 as a neighbour but node numer 8 isn’t getting any communications to work. Then I typicly need too reset controller in order for not ending up with alot of dead nodes that only take times to pass in a network heal. How do you typicaly solwe theese kind of problems. Node 7 and 8 is just about 1,5 meters (5 feet) apart. I think that it’s really starnge that node 8 could be dead but other noeds has number 8 as a neighbour.