Erdafitinib in Treating Patients With Relapsed or Refractory Advanced Solid Tumors, Non-Hodgkin Lymphoma, or Histiocytic Disorders With FGFR Mutations (A Pediatric MATCH Treatment Trial)

Inclusion Criteria: * Patient must have enrolled onto APEC1621SC and must have been given a treatment assignment to molecular analysis for therapy choice (MATCH) to APEC1621B based on the presence of an actionable mutation as defined in APEC1621SC * Patients must be \>/= 12 months and =/\< 21 years of age at the time of study enrollment * Patients must have a body surface area \>/= 0.53 m\^2 at enrollment * Patients must have radiographically measurable disease at the time of study enrollment; patients with neuroblastoma who do not have measurable disease but have metaiodobenzylguanidine (MIBG) positive (+) evaluable disease are eligible; measurable disease in patients with CNS involvement is defined as lesion that is at minimum 10 mm in one dimension on standard MRI or CT * Note: The following do not qualify as measurable disease: * Malignant fluid collections (e.g., ascites, pleural effusions) * Bone marrow infiltration except that detected by MIBG scan for neuroblastoma * Lesions only detected by nuclear medicine studies (e.g., bone, gallium or positron emission tomography \[PET\] scans) except as noted for neuroblastoma * Elevated tumor markers in plasma or cerebrospinal fluid (CSF) * Previously radiated lesions that have not demonstrated clear progression post radiation * Leptomeningeal lesions that do not meet the measurement requirements for Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 * Karnofsky \>/= 50% for patients \> 16 ye…