Is it common for a front tooth crown w/ a post to become loose & be replaced a year later with a larger, porcelain post?(photo)

Y front tooth had a root canal 25 years earlier. The original crown was placed with no post. That crown fell out with part if my tooth, one month after crown placement. A year later the crown was loose. The dr sent me home and told me to resume normal functions. It became looser within a few months and I saw a different dr. He said I probably need a larger post due to soft root canal filling and a porcelain post for aesthetic reasons and sent me home with a loose tooth again.