I’m in almost the exact same situation. I’ve been told that hiring managers generally understand that you probably can’t show your most recent work. Heck, some people can’t show any of the development process from their time at a firm because it would jeopardize the firm’s relationship with the client–even after the product is launched.
I’m working on my own side projects/revamping old student projects in order to have content for my portfolio. Luckily I do have a couple small work projects that are on the market. Does it matter if your employer finds out that you’re updating your portfolio? I think it’s pretty standard for IDers to be constantly evolving their folio.