What cultural faux pas should I try to avoid making in Kutna Hora?

"In Kutna Horaublic, it's important to respect the local customs and traditions. Avoid speaking loudly or behaving boisterously in public places, as Czech people are generally reserved and value their personal space. When visiting the Sedlec Ossuary, a chapel decorated with human bones, remember that it's a sacred place, not a tourist attraction. Treat it with the same respect you would any other religious site. Czech people are proud of their language, so try to learn a few basic phrases. However, avoid making jokes about the language or comparing it to other Slavic languages, as this can be seen as disrespectful. Tipping is customary in the Czech Republic, but don't leave the tip on the table. Instead, tell the server how much you want to pay in total, including the tip, when you're paying the bill. Avoid discussing sensitive historical topics, such as the Soviet era or World War II, unless you're well-informed about them and the conversation naturally leads there. Finally, punctuality is highly valued in the Czech Republic. If you're invited to someone's home, make sure to arrive on time and bring a small gift, such as flowers or chocolates," said another expat in Kutna Hora, Czechia.