issues with automatics switching voices in diferent apps by voiceOver.

Hello everyone. I'm using VoiceOver on my iPhone 14. The system is set to the Croatian language. Therefore, I'm using eSpeak NG as my synthesizer. It works quite well; however, in some applications, there's an automatic voice switch. For example, when I open Lazarillo, Sullivan+, and some other apps, instead of the eSpeak voice, I hear a voice from the English language area. Now, imagine how challenging it is to understand Croatian words when they're read by an English voice. Is there a way to disable this automatic voice change feature? I'm completely satisfied using eSpeak NG as my synthesizer and wouldn't want other voices to switch automatically. Someone might suggest deleting the English speech unit as a solution, but I can't do that since I work for an American company and frequently communicate with people from English-speaking areas. So, I need English speech synthesis for those situations.