I am using Ubuntu 22.04 and LibreOffice 24.8.4.2.
I put :mq: in Replace field and Å in with field. Actually I wish whenever I type mq even without space in Kruti Dev Font it should change to ऊ. Sometimes it works but after sometime the entry is automatically got deleted. I also notice some other entries which I make in Autocorrect got automatically deleted. What is the solution for this problem.
Maybe your user profile is getting corrupted. Does your computer crash? Do you close and wait for LibreOffice to close before shutting down your operating system. Do you share a login with other people? Do you see error messages?
I resetted user profile of LibreOffice several times. Mu Ubuntu take too much time to start and too much time to stop. It gives several prompts stating starting and stopping.
When you reset your user profile you lose all your custom AutoCorrect words amongst other things. These can be restored if you have saved the user profile under another name or elsewhere. Please read my link on what is in the user profile, backing it up, how to reset it manually, and adding folders back after manual reset