@KenjiBailly On Satellite Decos you won't be getting speeds faster than on Main Deco. For that reason, if you'd like to troubleshoot slow speeds we should start with Main Deco. Here is what I would...

@Sheepie Deco XE75 mesh will operate in Access Point mode just fine.

@Yohome I used that on my M5s, and it worked. I don't have X60s to test with. If nobody suggests anything else and you are somewhat desperate, you may be able force new firmware on X60s through...

@steevi2307 One more thing: if you can configure your Deco mesh to run in Access Point mode, try that and see if NAS goes to sleep now. Switching a Deco to Access Point (AP) Mode

@steevi2307 As a fellow Synology NAS owner I would suggest you google and read "What stops my Synology NAS from entering Hibernation?" from Synology Knowledge Center. The list of possibilities is...

@karakan08 You can have that topology if you run Deco mesh in Access Point mode. Switching a Deco to Access Point (AP) Mode