having problem with indi using Chart.SetYRange after update

I have on my charts some wide channels which bands are usually way above and below price bars visible on the chart (for the sake of the example, let's say Keltner Channel with periods 100 and band distance 20), and because cTrader automatically fits them inside the visible chart area (really wish it wasn't automatic), the price bars become unnecessarily compressed vertically (flattened). So some time ago I've written simple indi that stretches the chart vertically so that the current price bars fit the visible chart area. The indi uses Chart.SetYRange and after the last update it kinda stopped working properly. Yesterday I noticed that it works fine on a newly opened chart (but not on the "old" charts, which were already opened on the workspace), so I reopened all the charts I use, loaded my templates and it worked normally. I thought that it might be some one-time freeze because of the update, however, today when I opened cTrader, the problem returned - charts y dimension seems to be frozen to the default platform compressed view - i.e. fitting all the indicator lines inside visible space... and no action (like refreshing etc.) changes it. What's interesting even cbot with only one line of code:

protected override void OnStart()
        {
            Chart.SetYRange(135.0, 136.0);
        }

doesn't change the y range of such "frozen" chart, whereas it works on the newly opened one. Unfortunately the issue is difficult to replicate - when I close cTrader and reopen it a few seconds later, the indi is working on the chart I opened today, but not working on the charts I (re)opened yesterday.

Below is the indi code, it has some additional tweaks, but I don't think they got anything to do with the issue. And I checked - no other indicators used in the templates use the SetYRange function or got anything to do with resizing the chart.

using System;
using cAlgo.API;
using cAlgo.API.Internals;
using cAlgo.API.Indicators;
using cAlgo.Indicators;

namespace cAlgo
{
    [Indicator(IsOverlay = true, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class OT_chart_zoom_dynamic_height : Indicator
    {

        private double min;
        private double max;
        private int bars_back;
        private double HL_min;
        private double HL_max;
        private int desired_chart_height;

        

        protected override void Initialize()
        {
            Timer.Start(1);
            
        }

        public override void Calculate(int index)
        {
            bars_back = Chart.MaxVisibleBars;
            


            HL_min = Bars.LowPrices.Minimum(bars_back);
            
            HL_max = Bars.HighPrices.Maximum(bars_back);
            

            var height = HL_max - HL_min;

            if (TimeFrame == TimeFrame.Minute15)
            {
                desired_chart_height = 180;
            }
            else if (TimeFrame == TimeFrame.Minute)
            {
                desired_chart_height = 75;
            }
            else if (TimeFrame == TimeFrame.Hour)
            {
                desired_chart_height = 200;
            }
            else if (TimeFrame == TimeFrame.Hour4)
            {
                desired_chart_height = 300;
            }
            else if (TimeFrame == TimeFrame.Daily)
            {
                desired_chart_height = 400;
            }
            else if (TimeFrame == TimeFrame.Weekly)
            {
                desired_chart_height = 500;
            }
            else
            {
                desired_chart_height = 75;
            }


            var margin = 0.1 * desired_chart_height;

            if (height / Symbol.PipSize < desired_chart_height)
            {

                min = HL_min - (desired_chart_height * Symbol.PipSize - height) / 2 - margin * Symbol.PipSize;
                max = HL_max + (desired_chart_height * Symbol.PipSize - height) / 2 + margin * Symbol.PipSize;
            }
            else
            {
                min = HL_min - margin * Symbol.PipSize;
                max = HL_max + margin * Symbol.PipSize;
            }


        }
        protected override void OnTimer()
        {
            if (Chart.LastVisibleBarIndex == Chart.BarsTotal - 1)
            {
                
                Chart.SetYRange(min, max);
                
            }
        }

    }

}

Any help with that issue will be appreciated. Also, I'm not proficient in coding, so if there is a better way to stretch the chart vertically, please let me know.

Btw, is there a way to code indi lines so that they are not treated as an object which must be considered in automatic scaling of the chart? I remember I couldn't get around it - only objects not produced with [Output], like e.g. horizontal lines generated inside the for{} loop could be all over the chart and it wouldn't compress because of them.