In the example you gave, the xpub is generated is m/44'/0'/0'. Because of this, there is absolutely no point changing these numbers, since whatever your code is doing it is starting from this derivation path and deriving further. You should therefore always start with m/44'/0'/0'.

The test mnemonic you gave generates the address you were looking for at m/44'/0'/0'/5/0.

Based on this, your coins should be at m/44'/0'/0'/x/0, but you said you tried this and couldn't find anything? Are you sure the test mnemonic/xpub/address you gave above was generated with the exact same code as your real wallet?