BouncyCastle SCrypt using more memory than native impls?

I recently switched out the SCrypt implementation in my app. I had been
using native code: https://github.com/wg/scrypt. For reference, the code
I had been using was removed via this commit:
https://github.com/bitcoin-wallet/bitcoin-wallet/commit/83210d60461182188be8e13133a9bee40eefd1da

I'm now using BouncyCastle org.spongycastle.crypto.generators.SCrypt
(artifact: org.bouncycastle:bcprov-jdk15on:1.60)

I now have the problem that on low-end Android devices my app gets a lot
of OutOfMemoryErrors. I wonder if the BouncyCastle implementation
somehow uses more memory than it should, e.g. by copying buffers?

Is this maybe a known problem? I scanned the BCs issues at GitHub but
didn't find much about SCrypt at all.

By the way: on modern Android devices (Pixel 2, Android 9, 64 bit) the
BouncyCastle implementation actually runs faster than the native code
before!