Reading your first posts and the response from others, I am sure you exposed your seed and someone stole the funds. It must be someone who is close to you and he did not have good experience. He discovered different wallets and moved the funds. Sorry for you loss.
Which secure BTC Wallet do you recommend for me to hold?
It still a hardware wallet. I do not recommend ledger anymore.There are many other companies who are popular. Buy one that is convenient for you. But most importantly, do not type any of the seed on a digital device. Take a pen and paper or punch the letters on a metal sheet to make the seed fireproof but never write it in a digital device.