I’ve experienced similar results. Since pools closed I took those days and worked with stretch cords and on core activation drills. This past week I’ve been at my hometown in Michigan and have been Doing OWS each day. While the water is cold, I’ve been surprised that I haven’t lost much swimming endurance over the past three months of no swimming.
I think the dry land stuff helped for me in feeling how to engage my back muscles and keeping my elbows high (granted I have no swimming background so the bar was set low 🙂 ).