Time: always since 2.28 version update
Frequency: always since 2.28 version update
World name: Sargatanas
Character name: Shelke Rui
Class/level: White Mage/50
Party or solo: either way
Race: Miqo'te
In-game time: always
Area and coordinates: anywhere
Steps:

Set external keyboard type to Russian in PS4 Settings-Devices-External Keyboard, turn on Russian keyboard and dictionary in Settings-Languages. Can even try setting system language to russian, even though thats not necessary.
Log on your character, try typing in russian by using any combination of left-ride side Ctrl, Alt, Shift, ~. Nothing works, input language stays english.

Tried typing in japanese by switching external keyboard type to Japanese in Settings-Devices-External Keyboard and turning on Japanese keyboard and dictionary in Settings-Language. Can switch from japanese to english and back with ~ without problems.
Can switch external keyboard from english to russian in other PS4 games and on PC version of Final Fantasy XIV with Alt+Shift, so the issue is in PS4 version not recognizing russian keyboard type. Virtual PS4 keyboard brought up by pressing triangle on gamepad is working fine, switches with Alt+Shift like it should, but its an inconvenient way of communication.
With version 2.2 i could type in russian on PS4 without any issues, by switching with Alt+Shift. With 2.25 Alt+Shift stopped working and switching was possible with ~. Since 2.28 neither works.

Please fix russian external keyboard usage in game back to Alt+Shift functionality. The problem is narrowed down to PS4 version of Final Fantasy XIV from 2.25 and on.
There are no other reports on this particular problem, neither was it solved in patch 2.3 as part of "An issue wherein players could not enter Japanese with an English alphanumeric keyboard."
Please dont ignore a large number of your playerbase just because as far as you're concerned PS4 version has english and japanese input language and the rest are irrelevant. It was very nice to see the PS4 version recognising russian on its launch just like PC version, only for it to be taken away later.

Connection Specs

Type of internet connection/provider: optic fiber 100 mbit/s
Modem maker/model number: Asus RT-N16

Model Number of the PlayStation 4 You Are Using
- Model Number: CUH-100BA/B01

Information About the Peripherals You Are Using
-Type: keyboard
-Maker: Microsoft
-Model Number: 1093