It sounds like a caching issue (server caching, not the browser cache).
Views has its own caching mechanism. When using the legacy editor where you insert your View via shortcode, try adding the cached="off" attribute, e.g.
[wpv-view name="dogs-for-sale-view" cached="off"]
But if this used to work okay and no longer does, it sounds like a 3rd party caching solution may be affecting the results.
Try temporarily disabling 3rd party caching solutions to see if it resolves the problem.