This problem seems to happen for every number between 1000
to 9999.99999...
when using any spanish locale
(9999.99).toLocaleString('es')
"9999,99" // should be "9.999,99"
(10000.01).toLocaleString('es')
"10.000,01"
Is this a bug or part of the locale standard?.
Tested in the console on Chrome and Firefox