Blazor Server Application manage list item for multiple users

I am new to Blazor and have a basic question which I am not sure how to acheive this. I am building a POS Application in which users will have Touch application to sell products.

Now, I have all products loaded in a list below:

private List<ProductModel>? Products = [];

Which gets updated when user selects e.g. quantity increments when selected for sale and decrements when removed from sale. The good part is if I run 2 or 3 or 4 browser with same URL the quantity is shared across. Meaning you can run adjacent touch apps with shared list object and prevents from over selling.

However, I have search on the page as well which filters out the product that are displayed. Below is my code for Searching filter :

public async void OnSearch(string args){    if (isChecked == true)    {        if (args != "")        {            // Filter products where VariationCombinations is null            var productsToRemove = this.Products                .Where(x => x.ProductSiteAuth.Any(y => y.VariationCombinations == null))                .Where(e => (e.Name != null && !e.Name.ToUpper().Contains(args.ToUpper()) ||                            (e.Short_Name != null && !e.Short_Name.ToUpper().Contains(args.ToUpper()))))                .ToList();            // Remove the filtered products from the original list            foreach (var product in productsToRemove)            {                this.Products.Remove(product);            }            this.Products.ForEach(product =>            {                product.ProductSiteAuth?.RemoveAll(auth =>                    auth.VariationCombinations != null &&                    (                        (auth.VariationCombinations.Product_Variation_Combination_Name != null && !auth.VariationCombinations.Product_Variation_Combination_Name.ToUpper().Contains(args.ToUpper())) ||                        (auth.VariationCombinations.Product_Variation_Combination_Short_Name != null && !auth.VariationCombinations.Product_Variation_Combination_Short_Name.ToUpper().Contains(args.ToUpper()))                    )                );            });        }        else        {            Products = await CacheService.GetDataAsync(CacheKeys.ProductsCache, ProductService.GetProductsList, new CacheOptions { SlidingExpiration = TimeSpan.FromMinutes(30) });        }    }    else    {        if (args != "")        {            this.Categories = this.Categories.FindAll(e => (e.Title.Contains(args) || e.SubTitle.Contains(args) || e.Content.Contains(args) || e.Title.ToLower().Contains(args) || e.SubTitle.ToUpper().Contains(args.ToUpper()) || e.Content.ToUpper().Contains(args.ToUpper())));        }        else        {            this.Categories = CategoriesModel.GetCategories(this.FilteringValue).Result;        }    }    StateHasChanged();}

The issue I am facing in the code is that now since all browser tabs on same URL pointing to same shared product list, when 1 user on 1 tab searches it removes item from Product list and other users get issue when selecting that product, or if one 1 user searches product and the other user refreshes page they see filtered products as well.

How can I make search independent for each user where as share product list for quantity management ?

Please advise or at least guide me how can I do this ?

I want to share list for quantity management but for front end display it should not share products list.