Are foundation issues a reason to sell a duplex?

[Christopher Oliva]

I own a duplex that is unfortunately starting to show signs of foundation issues (floors becoming uneven, cracked tiles, hairline cracks in the wall, doors won't close, etc). The issues aren't bad right now, but the signs are certainly there. I bought this place a few years ago with the intention of keeping it as a long-term buy and hold, but now with the foundation issues starting to slowly show themselves I'm wondering if I should sell before the foundation problems get worse and make the Duplex hard to sell.  

What do you all think? Should I look at selling and moving on from this duplex or am I over thinking the foundation stuff?