How to Return a Custom Cell Size Calculator for MessageKind.custom in MessageKit?

Question

I'm using MessageKit in my iOS project to create a custom chat interface and I've run into a problem when trying to return a custom CellSizeCalculator for my custom cell that displays a series of buttons.

I have followed the MessageKit documentation to set up my custom cell and size calculator. Despite this, I'm receiving a fatal error that says "Must return a CellSizeCalculator for MessageKind.custom(Any?)". This occurs even though I have provided a custom size calculator for the custom message kind.

Here's the relevant code snippet:

func cellForItem(at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> UICollectionViewCell {
        let message = messageForItem(at: indexPath, in: messagesCollectionView)
        
        switch message.kind {
        case .custom:
            // Dequeue and configure the first cell with buttons
            guard let cell = messagesCollectionView.dequeueReusableCell(withReuseIdentifier: CustomerVCCell.reuseIdentifier, for: indexPath) as? CustomerVCCell else {
                fatalError("Unable to dequeue FAQButtonCell.")
            }
            cell.configure(with: faqData, delegate: self, at: indexPath, and: messagesCollectionView)
//            cell.configure(with: faqData, delegate: self)
            return cell
        case .text:
            // Handle text messages for user and other user
            let cellIdentifier = MessageContentCell.reuseIdentifier
            guard let cell = messagesCollectionView.dequeueReusableCell(withReuseIdentifier: cellIdentifier, for: indexPath) as? MessageContentCell else {
                fatalError("Unable to dequeue MessageContentCell.")
            }
            cell.configure(with: message, at: indexPath, and: messagesCollectionView)
            return cell
        default:
            fatalError("Unknown message kind")
        }
    }
}

import MessageKit

class MyCustomMessagesFlowLayout: MessagesCollectionViewFlowLayout {
    lazy open var customMessageSizeCalculator = FAQButtonCellSizeCalculator(layout: self)

    override open func cellSizeCalculatorForItem(at indexPath: IndexPath) -> CellSizeCalculator {
        if isSectionReservedForTypingIndicator(indexPath.section) {
            return typingIndicatorSizeCalculator
        }
        let message = messagesDataSource.messageForItem(at: indexPath, in: messagesCollectionView)
        if case .custom = message.kind {
            return customMessageSizeCalculator
        }
        return super.cellSizeCalculatorForItem(at: indexPath);
    }
}