Bug on YY/MM/DD date format?

Hello everyone, I'm making a simple clock with date. I'm using the DS1302.h library for the Real Time Clock and the LiquidCrystal_I2C.h library for the 16x2 I2C LED display.

On the first row I print the clock, on the second row I print the date. If the date is:

lcd.print(rtc.getDateStr(FORMAT_SHORT, FORMAT_LITTLEENDIAN, '/');

I obtain let's say the today date in DD/MM/YY: 25/04/20. And this works fine.
The problem is when I need the date in YY/MM/DD format.
I write:

lcd.print(rtc.getDateStr(FORMAT_SHORT, FORMAT_BIGENDIAN, '/');

Here what I get:
20 and slash is year and the separator, the "h" is the second number of the hours, then minutes and seconds. So 20/2:33:50 if time is 12:33:50.
Is a bug i think, maybe bad library? bug on hardware?

Actually I'm fine with DD/MM/YY format so my project can proceed, but I'm curious in what you think.

Library Manager doesn't know of a "DS1302" library. The known libraries that match "DS1302" are "Rtc by Makuna" or "RTCLib ny NeiroN". Did you mean one of those?

Ah! No, the library I sayd is correct: DS1302.h

But you got a point johnwasser! I think I used that library for testing and I dont remember where I downloaded it. I try to use the other libraries for more compatibility.

Thank you