Scrolling stopping with images in UITextView in a UITableViewCell

Question

In my app I have a UITableView of posts. In those UITableView cells there are UITextViews with parsed HTML to an NSAttributedString.

I resize the images before the tableview is populated in a model

let mutableText = NSMutableAttributedString(attributedString: text)
                mutableText.enumerateAttribute(NSAttributedStringKey.attachment, in: NSMakeRange(0, mutableText.length), options: .init(rawValue: 0), using: { (value, range, stop) in
                    if let attachement = value as? NSTextAttachment {
                        let image = attachement.image(forBounds: attachement.bounds, textContainer: NSTextContainer(), characterIndex: range.location)!
                        let screenSize: CGRect = UIScreen.main.bounds
                        if image.size.width > screenSize.width {
                            attachement.bounds = CGRect(x: 0, y: 0, width: image.size.width * ((screenSize.width-75)/image.size.width), height: image.size.height * ((screenSize.width-75)/image.size.width))

                        }

                    }
                })

However, when I scroll on the TableView the performance is horrible. When I reach an image it stops scrolling for half a second. Without images, scrolling is quite smooth.

EDIT: Here is what the tableview looks like