Grundig Removed Audiohub App Without Notice

I purchased a Grundig Portable 360 Bluetooth speaker. This speaker is advertised as having equalizer and tone control settings, and the ability to pair multiple speakers of the same type using the same app, all through the Grundig Audiohub app, which can be downloaded from the Google Play Store or Apple Store. However, after receiving the product, I couldn't find the Grundig app on the Play Store. I learned that Grundig had discontinued the app. When I asked Grundig about the issue, they could only say that the app had been removed. They offered neither a reason nor a solution. So, without the app, the product you purchased was rendered no equilizer control and unable to be paired with speakers of the same type as advertised. Nowhere did it mention that the features advertised on the product they were selling had been removed. Grundig still lists these products with those features on its website. The user manuals state that this app must be downloaded, and the manual includes a QR code for downloading. This arbitrary practice by Grundig violates commercial ethics, violates consumer rights, and could seriously damage its long-established brand image. Having used Grundig's products before and considered it a reliable and trustworthy company, I've now realized that it's not as trustworthy as I thought. I want to warn consumers that features advertised when purchasing a Grundig product may have been removed without notice.