Might not be arms deals, but China is making billions of investments in Central and South America.

I’m pretty sure they don’t actually want to escalate tensions with one of their biggest customers. It just doesn’t make sense for them. The US however is in a catch 22. US companies save tons of money by manufacturing in China but Chinese economic growth threatens the geopolitical dominance the US has enjoyed since WW2.

There isn't much value in doing so.

The USA doesn't have any disagreements with other countries in the Caribbean regarding claims to the sea like China has with its neighbors.

China would need to invest a significant amount of funding into arming Cuba in such a way as to enforce an embargo of the Gulf Coast. Even then, it isn't anticipated that Cuba could hold it long to an invasion. If Cuba could hold on, the USA could still use its other two coasts to ship goods.

And it isn't like China doesn't have economic access to the region.

China doesn't actually want a war, nor do they want to give any indication that they want to escalate tensions.

China stands the most to gain in a peaceful world order where they never have to use their military. Their military doctrine is defensive in nature, as is their nuclear doctrine (which, contrary to US/Russian policy, explicitly prohibits first-strike capability).

With a peaceful world order, relations with Taiwan can be normalized and the economy can continue to grow without impediment. Without the threat of encirclement and invasion, China doesn't have much means to justify their military budget (given that they are already regionally superior and have no real global power projection capability) and would see much more domestic backlash to their rapidly expanding military. China's core domestic geographical goals are to secure a more robust supply of O&G, secure the Himalayas as their southern border against potential Indian aggression, and prevent Xinjiang from devolving into a humanitarian crisis as it tries to integrate the (previously) predominantly rural Xinjiang population into the urbanized world that China has created.

When US-China relations were better back in 2018, the US even helped Chinese interests by striking ETIM training camps near the border between China and Afghanistan.

China is an economic power, not a military power. They like to get influence by giving loans, rather than by selling weapons.