The full answer
Yes — toasters are one of the most common sources of cross-contact
A shared toaster used for regular bread will leave crumbs that easily transfer gluten to gluten-free bread toasted in it afterward, making it one of the highest-risk items in a shared kitchen.
How to reduce the risk
The safest options are a dedicated gluten-free toaster, toaster bags, or using a clean oven/toaster oven instead — small, low-cost changes that meaningfully reduce cross-contact risk in a shared kitchen.
Important context
Individual symptoms, reactions, medical histories, food products, and local labeling rules can vary. Community experiences are not medical evidence.
For personal medical decisions, diagnosis, testing, or treatment, consult a qualified healthcare professional.