Can`t download my world

I want to download my world to change core, but download go very slow and always 0%. If wait for a little time, download says Network error: Aborted (i bad at English, so translate can be not accurate). I check my internet speed - it`s normal. I pinged Aternos, all answered (min - 45ms max -45ms). Tried to download from - opera gx (google) and microsoft edge (Yandex). If it can help - I`m from Russia. (Sorry for mistakes)

Wait, a tried to download my world 3 times. And when I asked for help, it downloaded. Sorry.