It is quite normal for Duty Finder to shift you between multiple queues. For example, let's say you are a DPS, it might shift you between two parties to see if there's a match:

2/3, 2/6, 1/15 (party of 2 tanks and 2 healers queued)
2/3, 1/6, 2/15 (party of 2 tanks, 1 healer and 1 DPS queued)

Another possibility is it shifting between languages queued. Each of these parties may have a separate, inidividual language selected. One of them English, the other Japanese.

As for it affecting multiple raids, it's possible to queue for multiple of them at once.

Unless there is more substantial proof of botting than this, you are likely just observing how the matching system works.