Quote from: Mayhys31 on Today at 02:15:31 PM

When I try to sync BRD with normal sync, arrived around 32% of sync, my balance is divided by 100 like on electrum. I stopped the normal sync on BRD. I reinstalled the BRD wallet and in fast sync, my initial balance reappeared.

That sounds like a transaction has been made that spent exactly 99% of your bitcoins.

Quote from: Mayhys31 on Today at 02:15:31 PM

• Why the balance is different between BRD fast sync and electrum ? (I read somewhere that multibit HD had very low low fees )

BRD wallet's fast sync mode is basically a centralized SPV on BRD's servers so it's also possible that the balance reported by BRD wallet may be completely wrong (when in doubt, check your address balance in a block explorer).

A wallet's fee rate does not affect how much bitcoin you see in addresses of two different wallet software.

Quote from: Mayhys31 on Today at 02:15:31 PM

• They advice me "normal sync mode" and to wait until final synchronisation, according to them, I have no risk to loose my initial balance (because of fees) during sweeping process.

You should do this. This will synchronize with regular SPV servers and they should report the correct amounts. It shouldn't take very long either, at most several seconds or possibly a couple of minutes.