.htaccess - trialing slash code effecting mysql query or making html inputs empty -

i using below trialing slash code in htaccess

rewritecond %{request_filename} !-f

rewriterule ^(.*[^/])$ /$1/ [l,r=301]

but while login website query not running properly... showing "select userid,profile_id,email,first_name,last_name,password,login_flag,usertype user email='' , password='$password' , usertype=' ' "

if remove above trialing slash code htaccess query working fine.

this website link https://www.reqsbook.com/login

and actual htaccess like

rewritecond %{http_host} !^www.

rewriterule ^(.*)$ https://www.%{http_host}%{request_uri} [l,r=301]

rewritecond %{https} off

rewriterule ^(.*)$ https://%{http_host}%{request_uri} [l,r=301]

rewritecond %{request_filename} !-f

rewriterule ^(.*[^/])$ /$1/ [l,r=301]

please me out not understanding why trialing slash code effecting query. how have update htaccess file