diff --git a/src/client/io_loop.rs b/src/client/io_loop.rs
index 4e86a5a22..d82a6da6c 100644
--- a/src/client/io_loop.rs
+++ b/src/client/io_loop.rs
@@ -282,8 +282,18 @@ impl<T: InvokeUiSession> Remote<T> {
                         }
                         _ = status_timer.tick() => {
                             if self.watchdog.check(self.is_connected, self.first_frame, self.handler.is_default(), Instant::now()) {
-                                log::warn!("No first video frame received, sending refresh");
-                                let display = self.handler.lc.read().unwrap().peer_info.as_ref().map(|p| p.current_display).unwrap_or(0);
+                                let (id, display) = {
+                                    let lch = self.handler.lc.read().unwrap();
+                                    let display = lch
+                                        .peer_info
+                                        .as_ref()
+                                        .map(|p| p.current_display)
+                                        .unwrap_or(0);
+                                    (lch.id.clone(), display)
+                                };
+                                log::warn!(
+                                    "No first video frame received, id={id}, display={display}, sending refresh"
+                                );
                                 self.handler.refresh_video(display as _);
                             }
 
@@ -1292,8 +1302,14 @@ impl<T: InvokeUiSession> Remote<T> {
         if let Ok(msg_in) = Message::parse_from_bytes(&data) {
             match msg_in.union {
                 Some(message::Union::VideoFrame(vf)) => {
+                    let display = vf.display as usize;
                     if !self.first_frame {
                         self.first_frame = true;
+                        log::info!(
+                            "First video frame received, id={}, display={}",
+                            self.handler.get_id(),
+                            display
+                        );
                         self.handler.close_success();
                         self.handler.adapt_size();
                         self.send_toggle_virtual_display_msg(peer).await;
@@ -1301,7 +1317,6 @@ impl<T: InvokeUiSession> Remote<T> {
                     }
                     self.video_format = CodecFormat::from(&vf);
 
-                    let display = vf.display as usize;
                     if !self.video_threads.contains_key(&display) {
                         self.new_video_thread(display);
                     }
diff --git a/src/server/connection.rs b/src/server/connection.rs
index 3670fb7cf..98397762c 100644
--- a/src/server/connection.rs
+++ b/src/server/connection.rs
@@ -3406,6 +3406,12 @@ impl Connection {
     }
 
     fn refresh_video_display(&self, display: Option<usize>) {
+        log::debug!(
+            "refresh_video_display: conn_id={}, display={:?}, source={:?}",
+            self.inner.id,
+            display,
+            self.video_source()
+        );
         video_service::refresh();
         self.server.upgrade().map(|s| {
             s.read().unwrap().set_video_service_opt(
diff --git a/src/server/video_service.rs b/src/server/video_service.rs
index 77bfa9ed4..d276a0ef3 100644
--- a/src/server/video_service.rs
+++ b/src/server/video_service.rs
@@ -650,6 +650,7 @@ fn run(vs: VideoService) -> ResultType<()> {
     let repeat_encode_max = 10;
     let mut encode_fail_counter = 0;
     let mut first_frame = true;
+    let mut logged_invalid_frame = false;
     let capture_width = c.width;
     let capture_height = c.height;
     let (mut second_instant, mut send_counter) = (Instant::now(), 0);
@@ -722,6 +723,24 @@ fn run(vs: VideoService) -> ResultType<()> {
         let res = match c.frame(spf) {
             Ok(frame) => {
                 if !frame.valid() {
+                    if !logged_invalid_frame {
+                        logged_invalid_frame = true;
+                        match &frame {
+                            scrap::Frame::PixelBuffer(f) => {
+                                log::debug!(
+                                    "capturer returned invalid frame (pixelbuffer), len={}, w={}, h={}, treating as WouldBlock",
+                                    f.data().len(),
+                                    f.width(),
+                                    f.height()
+                                );
+                            }
+                            scrap::Frame::Texture((texture, _)) => {
+                                log::debug!(
+                                    "capturer returned invalid frame (texture={texture:?}), treating as WouldBlock"
+                                );
+                            }
+                        }
+                    }
                     Err(std::io::Error::new(WouldBlock, "empty frame"))
                 } else {
                     repeat_encode_counter = 0;