Can't use with ADGUARD.

[ExcellentHzj]

Device:Sony Xperia XZ1
OS: Android 9
Shadowsocks version:5.1.2
Shadowsocks Service Mode:Proxy Only
Route:Bypass LAN & mainland China
Remote DNS:dns.google

Adguard Filtering method:Local VPN
Proxy:Enable
Proxy host:127.0.0.1
Type:socks5
Port:1080

DNS filters:
127.0.0.1:5450

Can't load some Gfw ban websites
for example:
Google.com
t66y.com
...

[christaikobo]

You need to use transparent proxy mode. As proxy only does not provide DNS service. It's fairly obvious since "DNS port" is grayed out.

Edit: my bad, looks like it was changed after 5.1.0.
I did some tests myself, seems Adguard is unable to connect to socks5 proxy with UDP profile enabled, when you check the "UDP over socks5" option.