Fundraiser Plugin translate when it shouldn't

Hi,
I am using the Fundraiser Plugin, and everything was fine, but suddenly it started to translate my text in several locations, even though get_locale() == 'en_US'.
Any ideas?

    Katya Tsihotska

    Hello Meital

    How are you?

    I've noted that you have the out-of-date version of the Fundraising. Please, try to update your plugin to the latest version and see if the issue still persists. But take a note, it would be better if you make a full backup of your site before changing something.

    If it doesn't help, I would need closer investigate your site to find a cause of the issue. Could you send us your details through our contact form https://premium.wpmudev.org/contact/#i-have-a-different-question using this template:

    Subject: "Attn: Katya Tsihotska"
    -WordPress admin username
    -WordPress admin password
    -login URL
    -FTP credentials (host/username/password)
    -link back to this thread for reference
    -any other relevant URLs

    Please use this subject line to ensure that it gets assigned to me.

    Also, it would greatly help if you attached some screenshots with the incorrect translations.

    Best regards,
    Katya