I found my lost seed and recovered my electrum wallet; only to find that wallet had been emptied. 10.78134 BTC gone, now 0.
What exactly do you mean by "now 0"? Does electrum show transaction where 10.78134
BTC is stolen/moved away? Does electrum show empty wallet? If it shows empty wallet, it's possible you entered wrong seed.
How did someone successfully hack my account.
FYI, Bitcoin protocol and Electrum doesn't have "account" system. There's no authority which can reverse the transaction or have log who accessed your wallet.
A lost wallet? How did you know that you successfully brute force the seed phrase? Likely the seed phrase may not be correct.
What makes you think OP brute force his seed phrase? All he said is "I
found my lost seed and ...".