PHP7.4 redis issue

I just updated php7.4-redis in ubuntu 18.04 server. After I get everywhere:

PHP Warning:  PHP Startup: Unable to load dynamic library 'redis.so' (tried: /usr/lib/php/20190902/redis.so (/usr/lib/php/20190902/redis.so: cannot open shared object file: No such file or directory), /usr/lib/php/20190902/redis.so.so (/usr/lib/php/20190902/redis.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0

I don't really understand what happened. This file is missing but all the others seem fine.

Is it a bug?

Any help please