I'm not sure if this is a Rust or Oxide thing but the "feature" seemed to disappear with Oxide 4433/4437.
I, like many others, use Steen's BotSpawn plugin and there's a config setting to let the profiles attack each other but now they cannot do damage to each other anymore.
I've even heard some other admins say that with Oxide 4439, autoturrets cannot do damage to npc's either.
NPC's are somewhat the foundation for a lot of the PvE servers so it would be nice to know about these changes if it is indeed an Oxide issue.

What is the solution for this ?

I'm really glad to hear the feature is coming back, it's a crowd-pleaser when players see the bots fighting each other.
So was this a change that FP did to Rust ?
If so, It sometimes feels like FP doesn't give a damn about the modded community.

btw., why was my image removed ?

Regarding the ban, I understand that the user was banned (maybe he grossly misbehaved or otherwise didn't follow the rules) and I understand that a connected external site/link was banned, but that the name itself cannot be written in the community seems VERY unprofessional.

Writing a name is hardly promotion and as an open community one would think that you would stay fairly neutral.
The user ban itself is, of course, fine as there are rules, but banning a word/name just comes off as petty and does not give the impression of an open community but more that of a personal website with personal "feelings" getting into the mix.
Hope you can "see" what I mean.

I imagine that my image was then removed because it contained the mentioned banned "word"...
If you look at the above statement objectively and knowing the word wasn't racist, toxic or in any other way offensive,  it would to any outsider "feel" communistic.