To install the latest eric6 version enter this command:
python3 -m pip install --upgrade eric-ide==21.11.
However, I recommend to upgrade to eric7 using this command:
python3 -m pip install --upgrade eric-ide
Please upgrade to latest eric6 release, which is r21.11, and report back, if the issue
Note, that eric6 will only get critical maintenance fixes through the repository but no
official release anymore. eric7 is the successor.