Is the word chegam the same in Brazilian and European Portuguese?

No

While the meaning, spelling, and conjugation of "chegam" are identical in both dialects, there is a difference in typical usage regarding the preposition that follows the verb when indicating a destination. In Brazilian Portuguese, it is much more natural and common to use the preposition em (and its contractions like no, na, num) to indicate arrival at a place. In Continental Portuguese, the preposition a (and its contractions like ao, à) is the standard and natural way to express arrival at a destination.

Additionally, the pronunciation differs: Brazilian Portuguese tends to have more open, clearly articulated vowels, whereas in Continental Portuguese, unstressed vowels are often reduced or nearly silent, making the "e" in "chegam" sound much shorter or almost swallowed.

Brazilian Portuguese Examples

1. Eles chegam em casa muito tarde. (They arrive home very late.)
2. Os pedidos chegam no aeroporto amanhã. (The orders arrive at the airport tomorrow.)
3. As encomendas chegam na loja na sexta-feira. (The packages arrive at the shop on Friday.)
4. Quando os ônibus chegam na parada? (When do the buses arrive at the bus stop?)
5. Os documentos chegam em breve. (The documents arrive soon.)

Continental Portuguese Examples

1. Eles chegam a casa muito tarde. (They arrive home very late.)
2. Os pedidos chegam ao aeroporto amanhã. (The orders arrive at the airport tomorrow.)
3. As encomendas chegam à loja na sexta-feira. (The packages arrive at the shop on Friday.)
4. Quando os comboios chegam à estação? (When do the trains arrive at the station?)
5. As notícias chegam a todo o lado. (The news arrives everywhere.)