I'll start by assuming "impossible to work with" means the functionality works but you can't see the array point behind the vertical double arrow cursor while moving it.
The cursor code in the TCL hasn't changed since at least 9-10 years, so maybe you are seeing a difference between Tk versions.
Date: Sat, 21 Mar 2020 14:19:40 +0100From: rolfm@dds.nlTo: Pd list <pd-list@lists.iem.at>Subject: [PD] cursor in array pd50 vs pd48Message-ID: <eac340396ecf5348f456b6caf30b49de@dds.nl>Content-Type: text/plain; charset="utf-8"; Format="flowed"hi(windows 10)just now i encountered a difference in cursor behavior in Pd 50 vs Pd 48 .attached is a picture when using the cursor in a graph.cursor 1: not pointing to a line in the graph - in both Pd's the samecursor 2: Pd48 pointing to a line (and possibly changing it)cursor 3: Pd50 idemcursor 3 is impossible to work with when one wants to change something in the graph,or even using it for reading a position in the graph.the array-in-datastructures-help can be used to illustrate this.how to change this?rolf