My two cents is to avoid the global heal. For me it makes a mess of everything, and was discussed here that it just doesn’t work well - 70 Zwave device network stuck healing for over 24hrs - #20 by HeyImAlex
Instead I heal individual devices that are slow or have routing problems/log issues, and possibly the ones physically around them. That seems to work well. Also, make sure any battery device you heal is awake.