Disables players during backup
(03:36:05) | *.*.*.*:65202/76561############/why frog? kicked: Packet Flooding: Player Tick

(03:36:05) | *.*.*.*:33496/76561############/SnoOpy kicked: Packet Flooding: Player Tick

(03:36:05) | *.*.*.*:57424/76561############/Nesferot kicked: Packet Flooding: Player Tick

server.maxpacketspersecond 2000

set the value higher, nothing helps

This plugin doesn't have much usecase. Might have 4 years ago, but the server keeps multiple map back ups, oxide keeps backup of plugins when changes are made. An increasing max packets will indeed make no difference. The server freezes up, when it is done, the client finally finds connection and floods all the pending requests to server, leading to a kick.

Just uninstall this plugin.

Is there any backup plugin for oxide?

Can you clarify your question? Oxide as in the oxide folder containing plugins / data / config?

Yes, all data files
oxide/plugin.../