Hi there is no pre-shared key. . I’ve just noticed that there is no persistent keep alive for the Mango client.
Will fix this and get back if this was not the problem

    option public_key 'x5Qk5gMhIN+XLNmTZWnJMnk='
	list allowed_ips '10.200.200.2/32'
	option route_allowed_ips '1'
	option persistent_keepalive '25'
	option endpoint_port '51820'
	option description 'OnePlus'

config wireguard_wg0
	option public_key 'xpmzQglyze+aQ1wI2wuErPR5nnDwY='
	list allowed_ips '10.200.200.3/32'
	option route_allowed_ips '1'
	option endpoint_port '51820'
	option persistent_keepalive '25'
	option description 'iPad'

config wireguard_wg0
	option description 'Xaomi'
	option public_key 'xL4ykRftzO/VFlPoUtkv113Kx8='
	list allowed_ips '10.200.200.4/32'
	option route_allowed_ips '1'
	option persistent_keepalive '25'

config wireguard_wg0
	option description 'Mango'
	list allowed_ips '10.200.200.5/32'
	option route_allowed_ips '1'
	option public_key 'xLv4ofuZOR8HH+AAdrmE='