Yes, they are all Shelly devices and they connect via wi-fi from the fritzbox.
Actually, I’m thinking whether the ip-scan tool is showing everything that ever got an IP while the Leases menu shows only the active ones?
Not sure I fully got what you are saying
Are you suggesting to have a MikroTik as a router and then a separate device/s as wired/wireless AP?
If so, do you suggest having the same brand (MikroTik) also for the APs or whatever brand?
IP scan tool is supposed to probe (ping or something) some address range and only display active devices. Doesn’t matter how those devices obtained their IP addresses (either by static settings or via DHCP lease … and the later can be either served by “local” DHCP server or by some other DHCP server serving same subnet). Leases menu shows devices which obtained their dynamic IP address from “local” DHCP server … since it started. Depending on DHCP server settings it might happen that after a reboot the leases list will be empty but that doesn’t mean devices don’t have valid IP addresses.
Yes, I’m saying that having separate MT router and separate AP has its merits. MT routers are mostly considered a very good choice by users advanced enough to be able to master MT (ROS has a bit steep learning curve and not everybody is able to get to the point where they can effectively administer their MT devices). While many Mikrotik wireless devices (APs) perform decently and mostly trouble free, it seem that MT devices are not supporting latest wireless standards (like 802.3ax) or they support only basic functionality and mediocre performance (the case with 802.3ac). So many users see APs from other vendors a very attractive alternative if you expect more than basic wireless performance.