updated to 2.3.4, still having the “endless spinning” problem. javascript console shows:
Uncaught TypeError: Cannot read property 'new_pos' of null
at Object.update_simple_ordering_callback [as success] (simple-page-ordering.min.js?ver=2.1:1)
at i (load-scripts.php?c=1&load[chunk_0]=jquery-core,jquery-migrate,jquery-ui-core,utils&ver=5.4.1:2)
at Object.fireWith [as resolveWith] (load-scripts.php?c=1&load[chunk_0]=jquery-core,jquery-migrate,jquery-ui-core,utils&ver=5.4.1:2)
at x (load-scripts.php?c=1&load[chunk_0]=jquery-core,jquery-migrate,jquery-ui-core,utils&ver=5.4.1:4)
at XMLHttpRequest.c (load-scripts.php?c=1&load[chunk_0]=jquery-core,jquery-migrate,jquery-ui-core,utils&ver=5.4.1:4)