Most folks here know what “clank” tone is. I was working on getting a similar Steve Harris tone 20 years ago, and I’m sure there are other folks on TalkBass who have been working to achieve that same tone for even longer than that.
It’s possible your setup isn’t the most ideal for achieving the tone you’re looking for, which is why in previous threads folks were recommending you learn how to do a setup yourself. If you hold down your first fret and last fret to the fretboard, how much space is between the bottom of the string and the top of the 8th-10th frets? Do the strings touch the frets? They shouldn’t. Can you just barely squeeze a business card in there? That’s pretty decent. Can you fit a credit card or something thicker in there? Your setup probably isn’t ideal.
In addition, I remember you wanting to use higher gauge strings. While string gauge isn’t synonymous for string tension, a heavy gauge typically means higher string tension which can hinder your ability to achieve “clank” tone. Steve Harris uses thick, high tension flatwound strings. They work for him, but they did not work for me. I personally use light gauge round wounds, and I have no problem getting clank when I want to.
Your playing technique can play a huge role in the sound you’re getting. Playing through the string and towards the pickup will help. You might have to hit the strings harder than you normally would if the setup isn’t ideal.
How new and fresh the strings are also plays a role. I know you got new strings put on recently so that shouldn’t be an issue, but if you’re playing 5+ hours a day and aren’t playing with clean hands and wiping down the strings once you’re done playing then they will dull out a lot quicker. Keep in mind, Steve Harris puts new strings on before every show he plays, and I believe I once read he does the same for each track he records in the studio. He strings are very new and fresh, and that helps him get his tone. Unfortunately, most people don’t have that kind of money to spend.
Lastly, it’s possible you just need to practice more. It took me probably 3-4 years before I personally thought I was having consistent, good tone. It takes times to figure these things out, so don’t get discouraged.