It is the approach that's the problem, not AI. Your router started with a perfectly good, well test config, that should be safe. It does not have VLANs, and you want VLAN for some reason. So if you allow an "raw" AI without an SKILLs/instruction/prompts/MCPs to "guide" it, it has to do a shit ton of guessing/probability at each line of new config. TL;DR: IDK your goals with VLANs but AFAIK your config lacks a good firewall, at the VERY least.
So if you provide it the stock default configuration (from export), and at miniminum prompt to ✨ Steering AI to use new manual.mikrotik.com you'll likely end up at much better starting place. Perhaps start by asking how to get back to default-configuration as the first step.
Now that still may not help that much unless your prompt more than "... I want to VLAN my network .... Like the "forum rules" suggestion: describe your problem not desired configuration. This applies equally to AI LLMs as does this forum.