Hey @ydrea,
I am glad to help. Go to Tools > Site Health > Info (At the top) and click Copy Site Info to Clipboard, then paste on a notepad and check for:
wp-media
post_max_size:
upload_max_filesize: wp-server
wp-server
max_input_variables:
time_limit:
memory_limit:
max_input_time:
upload_max_filesize:
php_post_max_size:
As these can be the limiting factor on how much you can push your server. Normally execution times are good to go at 300 seconds, Memory 250 minimum, post and upload as close as you can to your average payload.
You can try with a small number of images and increase gradually, or you can ask your hosting company to increase these values as much as they can.
Please keep me posted.
Have a good one.