Hi @Ruslan Narmatov,
Thanks for your trust. I am willing to support you.
According to the information provided and the research done, I may understand that the SharePoint App on your Android phone is not able to download the files in SharePoint Server. However, in this forum we are mainly responsible for SharePoint issues on the web or server side, we lack a relevant test environment and relevant information for the mobile side.
Currently, it would be advisable to post a new question in this community.
When you ask a new question, you can specify SharePoint App and Android. There will be teams there who have more knowledge about the mobile side to investigate the issue and help you find the root cause.
Please kindly notice that I am always on standby to support you. If there is anything unclear, please let me know.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. It will be beneficial to more community members reading here. Your contribution will be highly appreciated.