You can check download manger settings to select Bootstrap 4
If problem persists we need to check more.
Thanks
Current setteing is “Bootstrap 3”.
I changed “Bootstrap 4”, then I had another trouble.
Character “Download” in button disappered.
I’m in trouble both “Bootstrap 3 ” and “Bootstrap 4”
OK, it is css issue which is coming from your theme where you have defined a class .btn in https://www.digital-den.jp/simplelife/wp-content/themes/ultrarocketman/responsive.css
so there needs some css modification as your requirement.
Thanks
Thanks for your investigation.
The cause is for ultrarocketman ….
