Very, very slow time to load PL/SQL packages

Hi, using SQL Nav for many years (currently version 5.5 32 bits), we switched to version 7.6 for DB compatibilities and improvements with PL/SQL (i.e: ORACLE 19c).
While this release brings lots of new features, we experiment a very, very slow loading time for PL/SQL packages.
With a PL/SQL package of approx 16K lines, it takes nearly 20s to load (SQL Nav 7.6 64 bits instant client 21.10).
While same package with SQL Nav 5.5 32 bits (instant client 11.2) it takes 2s.
Does anyone has same issue?
Is there a quick fix?
Thank's for help.