Cancel open trade with unresponsive buyer

I am trying to sell some BTC. I clicked on an offer that a BTC buyer had posted and accepted the offer.

At the time I accepted the offer, the BTC price was considerably lower than it is now. The buyer has not made payment and it has been a day and a half so far. The offer I accepted requires the buyer to pay me via Zelle.

I can’t imagine why the buyer would want to delay making the payment, since the price he would pay is lower than the current BTC price. I sent him a chat msg last night asking him (nicely) to complete the trade, as I’m in a hurry to get it done (especially given the trend in price).

My question: Is there any way to cancel the trade at this point, since the buyer has not made any payment? I see no way to do that.

I realize there is a 4-day rule. Am I stuck waiting it out? If there is a way to cancel the trade, what are the ramifications for doing so with respect to the deposits involved?

Thanks for any advice

You are right in that you cannot just cancel the trade now that it has been opened, or rather, you can but you would face a penalty.
You should definitely wait for the trade period expiration, and if that is reached, you will get a compensation out of the buyer’s deposit, and will be able to cancel the trade then. Here’s hoping the buyer doesn’t become unresponsive

Here’s how Bisq deals with trades when they don’t go the happy path: Dispute resolution - Bisq Wiki