What happens to a Trader in production if I lose Trade Route capacity?

I know that it isn't possible to start production of a Trader if you don't have enough Trade Route capacity, but what happens if I'm already producing a Trader when I lose the capacity?

I'd like to know if the production continues and if it doesn't, if the spent production is lost or if it carries over. Based on what I've read elsewhere, excess traders become idle and can't establish trade routes until the capacity is increased, but that's for existing traders and not for traders in production.

To give you some context, I'm currently running a Merchant Republic and I'm considering switching to Monarchy, because most of my cities are short on housing and most of them have walls.

From personal experience, as this happens quite a lot in the newest expansion. The trader will still be created but you can not send it anywhere. The best thing to do is to let the trader sleep until you get another trade route, just remember that you have one.

From the fandom wiki:

Each Trader services one Trade Route. For this reason, when the number of traders reaches the trading capacity you can't build more Traders. Still, there are exceptional situations in which the number of Traders can exceed the trading capacity. This happens when your Trading Capacity suddenly decreases below the number of Traders you have. Trading Capacity may decrease for example in vanilla Civilization VI when you change governments from Merchant Republic to something else (which reduces your Trading Capacity by 2); or when you lose cities with commercial infrastructure. All the Trade Routes that were active when the decrease in Trading Capacity happened remain active. This means that the number of Trade Routes can actually exceed the Trading Capacity for a few turns. However, the next Trader (or Traders) to finish a Trade Route will be unable to start a new route and will be forced to stay inactive. They will recover their ability to create Trade Routes once you increase your Trading Capacity again.