You cannot aggregate links in the way you attempt to do.
First of all:
802.3ab is Gigabit Ethernet. It's not a aggregation protocol.
802.3i is 10Mb Ethernet.
802.3u is 100Mb Ethernet.
802.3x is Full Duplex 100Mb Ethernet
802.3p is not a recognized standard.
None of the stuff you mention your switch supports is even remotely relevant for aggregation. ...
Then I wonder about the 0.0.0.0 gateway in the printer's network config.
It would mean that your printer can connect to any IP address directly. Under normal circumstances, a system will only be able to communicate directly with other systems in its subnet (see the mask). For wider reach it'll need to go through a gateway.
You need to do some hardening on your router. There are lots of bots that just crawl the web looking for open servers / services.
Block inbound connections that are not absolutely necessary.
Add blackhole routes for the RFC 1918 address blocks, as suggested in the comments.
Change your admin credentials to something complex.
Is it possible that these were ...