Hi Team, the clean() function which helps in stripping additional spaces was not

There seems to be a disconnect between what the documentation says and what the rule definition says. The documentation, agreeing with your original assumption, says "Returns the specified text after stripping it of additional spaces between characters." Source: forum.appian.com/.../Text_Functions.html
Note: this seems to essentially duplicate what the trim() function says.

On the other hand, the in-system rule definition says "The function will return the provided text, minus any characters not considered printable. (Performs opposite function of strip.)" - see attached screenshot. Spaces definitely are "printable", so the behavior you're experiencing is consistent with this description.

There seems to be a disconnect between what the documentation says and what the rule definition says. The documentation, agreeing with your original assumption, says "Returns the specified text after stripping it of additional spaces between characters." Source: forum.appian.com/.../Text_Functions.html
Note: this seems to essentially duplicate what the trim() function says.

On the other hand, the in-system rule definition says "The function will return the provided text, minus any characters not considered printable. (Performs opposite function of strip.)" - see attached screenshot. Spaces definitely are "printable", so the behavior you're experiencing is consistent with this description.