When I specify an individual target,

>nmap -v3 -sn 172.18.188.209

I get the correct and expected nmap response

Starting Nmap 7.70 ( https://nmap.org ) at 2019-11-08 11:16 India Standard Time
Initiating Ping Scan at 11:16
Scanning 172.18.188.209 [2 ports]
Completed Ping Scan at 11:16, 1.00s elapsed (1 total hosts)
Initiating Parallel DNS resolution of 1 host. at 11:16
Completed Parallel DNS resolution of 1 host. at 11:16, 5.62s elapsed
DNS resolution of 1 IPs took 5.62s. Mode: Async [#: 4, OK: 1, NX: 0, DR: 0, SF: 0, TR: 3, CN: 0]
Nmap scan report for raspberrypi-dQ2XyAPpB6.dhcp.XXXX.com (172.18.188.209)
Host is up, received conn-refused (1.0s latency).
Read data files from: C:\Program Files (x86)\Nmap
Nmap done: 1 IP address (1 host up) scanned in 6.70 seconds

However, when I specify a range,

>nmap -v3 -sn 172.18.184,186,188.0-255

I get,

.
.
Nmap scan report for YYYY.dhcp.XXXX.com (172.18.188.208)
Host is up, received syn-ack (0.0010s latency).
Nmap scan report for 172.18.188.209 [host down, received no-response]
Nmap scan report for 172.18.188.210 [host down, received no-response]
.
.

I'm running Windows 10 version 1809 build 17763.737 and Nmap 7.70

Additional info if it helps

>nmap -version
Nmap version 7.70 ( https://nmap.org )
Platform: i686-pc-windows-windows
Compiled with: nmap-liblua-5.3.3 openssl-1.0.2n nmap-libssh2-1.8.0 nmap-libz-1.2.8 nmap-libpcre-7.6 WinPcap-4.1.3 (packet.dll version 10 nmap-libdnet-1.12 ipv6
Compiled without:
Available nsock engines: iocp poll select

Is this a bug, or am I missing something in the switches ?

Thanks !