Hi Ron,
Welcome to Affinity Forums :)
The tool you have been using is the Undo Brush Tool. I believe you wanted to use the Inpainting Brush Tool. To access it click the small arrow near the Healing Brush Tool (6th icon counting from bottom) to show a menu with more tools. The Inpainting Brush Tool is the second counting from bottom. To use it just paint over the element you want to remove from the image. To undo press ⌘ (cmd) + Z or go to menu Edit ▸ Undo. Here's a video tutorial that may help. For more tutorials check out this thread or our Vimeo Channel.
rontaube got a reaction from Persa in Free Content included with 1.6 ('Till 16th November)
rontaube reacted to MEB in Undoing with the in painting brush