Garbage collection unexpected results

I have narrowed down what is triggering the low memory (when run from RAM). I have the following class which is basically shifting the queue if push item and over max size:

export class Queue<T> {
    protected itemLimit:number;
    protected internalArray: Array<T>;

    constructor(itemLimit = 3) {
        this.itemLimit = itemLimit;
        this.internalArray = [];
    }

If I initiate 2 or more of these like this:

this.waypoints = new Queue<IWaypoint>(10);
this.waterways = new Queue<ILocalisedFeature>(10);

...the memory bottoms out. Which is curious as even if I comment out the initialisation of the array it still bottoms out.

The actual non minified compiled typescript looks as follows:

/***/ './src/constructs/queue.ts': /***/ function (__unused_webpack_module, exports) {
            eval(
                '\r\nObject.defineProperty(exports, "__esModule", ({ value: true }));\r\nexports.Queue = void 0;\r\nvar Queue = /** @class */ (function () {\r\n    // itemCount = 0;\r\n    function Queue(itemLimit) {\r\n        if (itemLimit === void 0) { itemLimit = 3; }\r\n        var _this = this;\r\n        this.lastN = function (count) {\r\n            if (count === void 0) { count = 2; }\r\n            var newAry = [];\r\n            for (var i = _this.length - 1; i >= Math.max(0, _this.length - count); i--) {\r\n                newAry.push(_this.internalArray[i]);\r\n            }\r\n            return newAry;\r\n        };\r\n        this.any = function () {\r\n            return _this.length > 0;\r\n        };\r\n        this.lastEntry = function () {\r\n            try {\r\n                return _this.internalArray[_this.length - 1];\r\n            }\r\n            catch (err) {\r\n                return null;\r\n            }\r\n        };\r\n        this.firstEntry = function () {\r\n            return _this.internalArray[0];\r\n        };\r\n        this.lastMinus = function (numberFromEnd) {\r\n            if (numberFromEnd === void 0) { numberFromEnd = 0; }\r\n            return _this.internalArray[_this.length - 1 - numberFromEnd];\r\n        };\r\n        this.clear = function () {\r\n            _this.internalArray.length = 0;\r\n        };\r\n        this.asArray = function () {\r\n            return _this.internalArray;\r\n        };\r\n        this.itemLimit = itemLimit;\r\n        this.internalArray = [];\r\n    }\r\n    Object.defineProperty(Queue.prototype, "length", {\r\n        get: function () {\r\n            return this.internalArray.length;\r\n        },\r\n        enumerable: false,\r\n        configurable: true\r\n    });\r\n    Queue.prototype.isEmpty = function () {\r\n        return !this.any();\r\n    };\r\n    Queue.prototype.push = function () {\r\n        var _a;\r\n        var items = [];\r\n        for (var _i = 0; _i < arguments.length; _i++) {\r\n            items[_i] = arguments[_i];\r\n        }\r\n        var n = (_a = this.internalArray).push.apply(_a, items);\r\n        if (this.itemLimit != null && this.itemLimit > 0) {\r\n            this.internalArray.splice(0, this.length - this.itemLimit);\r\n        }\r\n        return this.length;\r\n    };\r\n    return Queue;\r\n}());\r\nexports.Queue = Queue;\r\n\n\n//# sourceURL=webpack://ck_nav/./src/constructs/queue.ts?',
            );

            /***/
        },

I am wondering if the get overrides (such as below)

• which result in Class.prototype stuff is the cause but need to test more.

  get length() {
      return this.internalArray.length;
  }