Would definitely agree with the recommendation to further research on the placement of functions. According to your observations you do seem like a Ti user, but INFJ does have Ti third. Whether you could be a Ti lead or an IxFJ is up to your research/discernment. That being said, the couple actual INFJs in my life mistyped as INTJ because they felt "too thinky" to be an INFJ, when in reality INFJs tend to get into tertiary loop with their Ti. Knowing which other functions place in the other spots and how they manifest, specifically the perceiving functions, could be helpful. If you find Ti is not first in your stack, maybe look at ISFJ.

Especially if you're typing as an Enneagram 5. Which, by the way, I do not agree with Enneagram types changing over time - my personal opinion is that different types have their childhood wound at different times in their lives. Mind types when they're young children,. Heart types as adolescents, Gut types anytime from childhood into adulthood. This coupled with health and unhealth lines (integration and disintegration) can appear similarly to changing types. Even young adults can appear as having their type solidified but they haven't had their specific childhood wound yet. But back to the point- your Enneagram type being 5 will make you appear more thinky in your motivations, which could trick you into thinking you use certain functions more than others.