My autobid was outbid then the buyer removed the opposing winning bid - now my autobid is stuck at my maximum

Kia ora Terry. Yes, your bid should definitely be adjusted now that the leading bid has been removed. This isn't something that happens automatically with bid removals and auto-bids; we will need to take care of that manually for you. 
I'll let the team know about this, but in the meantime you can reach out on Chat and speak to an agent right away. 

While its possible the other bidder asked for their bid to be removed, there is no sign of that in the questions section (although could have asked on another of their listings) so it does look as though they may have an "alternate" account to do just this to obtain max bid and then back out. They seem to run many $1 reserve so may have developed a "skill" at this. You also have the right to ask the seller to remove your max bid and /or all bids. Not good to now put another Max bid in as you have revealed your hand and he can manipulate that in the last minutes of bidding

Thanks Donal, I wondered about that but I've won a few of their other $1 no reserve auctions and some were very low so I don't think that's whats happening here... Yeah, a bit annoyed it's revealed my max, but it's only a "placeholder" bid and I might go higher if I need to at the last minute depending on how busy I am at the time and how full the workshop looks...

If the leading bid was removed with no visible question on auction and within a very short time of actually being placed,

That is a sure sign possible shill bidding going on,

Make sure you get E-Mails when I am out bid and then you know if top bid has been removed,

also good in disputes if once out bid you have moved on and brought another, you have proof,

Trade Me can check listing which can draw attention to seller if they are up to no good,

as many many years ago My Auto bid was out bid, got E-Mail then minutes later a E-Mail that I won at my max bid?, no Q&A's for bid to be removed?, hmm what is going on here?. Alarm bells !!,

Good tip flossy63, thanks. In the other auctions I won from this bidder (local clearing out an estate) the (several) other bidders have hundreds of feedbacks so I think in this case it's all genuine. But I've set my notifications and I'll definitely look out for that from now on....