Unfortunately forum has some primitive issues that I reported, asking for a fix beforehand. You may try no

1- Do not copy paste images into the post and upload from the ßutton in "write a post" screen.

2- Upload the images one by one, not together.

3- Try to use a differwnt browser.

These are my common workarounds for forum image submitting. If neither of them works, you may consider submitting imgur or puush links of them so we could try to help you on your lineup at least even if not as convenient.