There is a free variable, third row went all zeros. So I have been handing in one point off an entire line this whole time.
Just use new = old[:], that is the standard way to copy a list.
One counterweight to all this: 40 signups is a very small sample. Nothing you learn from it will be statistically anything. Treat it as 40 conversations you have not had yet rather than as a dataset.
One more safety net if you are ever mid mess and unsure: git stash your uncommitted changes first so the working tree is clean. Nothing in git is dangerous to a clean tree except force pushing.
Two hundred a month against three weeks of your only engineering capacity is a bad trade on the raw numbers, roughly seven months of their revenue. It is only a good trade if it buys information or a market. Make sure you can say which one before you start.
Worth separating two clocks. Months since you started building is not very informative. Weeks since you started actively selling usually is. If you have been selling for one week out of five months, you are one week in, not five months in.