I think it was contaminated.

Pseudomonas may give a pigmented growth but clump formation raises the suspicion of possible contamination. U can do spot microscopy to check that from broth itself

Ps aeruginosa strains vary in their phenotypic behaviour regarding smooth/rough, mucoid, etc growth and this strain might be one that shows clumping in fluid media. Replate to check Dr Singh's suggestion of contamination, but if you get pure growth Ps aeruginosa then it is a clump- forming strain. This is often affected by cell hydrophobicity so you could try another medium