For stability reasons, try connecting to bootloader and flash first.

If the device is stuck in bootloader this will recover it.
If its not it will continue to warm flash.
And if the retries flag is on it will recover by safelink if both fail

conftest.py

@@ -154,9 +154,14 @@ def flash(self, path: str, progress_cb: Optional[Callable[[str, int], NoReturn]]
                 targets = [Target('cf2', 'stm32', 'fw', [], [])]
             else:
                 targets = []
-
-            self.bl.flash_full(cf=self.cf, filename=path, progress_cb=progress_cb, targets=targets,
-                               enable_console_log=True)
+            try:
+                print('Trying cold flash')
+                self.bl.flash_full(cf=self.cf, filename=path, progress_cb=progress_cb, targets=targets,
+                               enable_console_log=True, warm=False)
+            except Exception as e:
+                print('Failed cold flash (as expected), trying warm flash')
+                self.bl.flash_full(cf=self.cf, filename=path, progress_cb=progress_cb, targets=targets,
+                    enable_console_log=True, warm=True)
         finally:
             self.bl.close()